Influence of storage temperature and duration on postharvest physico-chemical and mechanical properties of pomegranate fruit and arils

Abstract

Physico-chemical and mechanical properties for pomegranate (cv. Wonderful) were determined during 5 months of storage at 5°C, 7.5°C, and 10°C with 92% relative humidity (RH) and at 21°C with 65% RH. The results showed that weight loss increased with temperature and storage period. Only fruits stored at 5°C and 7.5°C lasted for 5 months, with a weight loss of 27.67% and 45.67%, respectively. Furthermore, the primary source of moisture loss was the fruit peel, and this resulted in over 30% reduction in peel thickness after a 5-month storage period. Colors of fruit and arils decreased with prolonged storage duration. Furthermore, total soluble solid (TSS), pH, TSS:titratable acidity, and BrimA increased throughout the storage period. Fruit puncture resistance as well as fruit compression parameters such as firmness, toughness, and bioyield decreased with storage temperature and duration. These findings showed that fruit should be stored between 2 and 3 months at 5°C to ensure the best internal and external quality attributes.

Durante cinco meses, se almacenó granada (cv. Wonderful) a temperaturas de 5°C, 7,5°C, 10°C con 92% humedad relativa (HR) y 21°C (65% HR), determinándose posteriormente sus propiedades físico-químicas. Se constató que la pérdida de peso fue mayor a medida que aumentaron las temperaturas y los periodos de almacenamiento. La fruta que se almacenó a 5°C y a 7,5°C fue la única que duró cinco meses, presentando pérdidas de peso de 27,67% y de 45,67%, respectivamente. Además, tras cinco meses de almacenamiento, se observó que la principal fuente de pérdida de humedad fue la cáscara, constatándose que su grosor se redujo en más de 30%. Asimismo, durante periodos de almacenamiento largos, se encontró que disminuyeron los colores de la fruta y de los arilos, elevándose los niveles de total de sólidos solubles (TSS), pH, TSS:acidez titulable y BrimA durante el almacenamiento. Se observó que a mayor temperatura y periodo de almacenamiento, disminuyeron la resistencia a la perforación y los parámetros de compresión de la fruta (firmeza, dureza y bio-rendimiento). Estos resultados demuestran que, para asegurar que la fruta desarrolle sus mejores atributos de calidad tanto internos como externos, deberá almacenarse durante un periodo de dos a tres meses y a una temperatura de 5°C.

Keywords:

• fruit quality
• storage conditions
• pomegranate
• South Africa

Palabras claves:

• calidad de fruta
• condiciones de almacenamiento
• granada
• Sudáfrica

1. Introduction

Pomegranates (Punica granatum L.) are commercially cultivated in many subtropical countries such as Tunisia, Turkey, Egypt, Spain, Morocco Iran, Afghanistan, India, Pakistan, and USA (Holland, Hatib, & Bar-Ya’akov, 2009; Stover & Mercure, 2007). Nearly all parts of the fruit can be utilized. The edible part (aril) contains sugars, vitamins, polysaccharides, polyphenols, and important minerals (Miguel, Nevesa, & Antunes, 2010). The peel is a rich source of natural antioxidants and has been used in the Middle East as colorants for textiles due to the high tannin and phenolic content (Al-Said, Opara, & Al-Yahyai, 2009; Li et al., 2006). The high antioxidant activities of pomegranate fruit are attributed to high levels of polyphenolic compounds, which act as good free radical scavengers (Fawole, Opara, & Theron, 2012). In the last few years, there has also been an increase in the demand for industrial processing of pomegranate arils for fresh consumption and processed products such as food colorants, tannins for leather, jellies, jams, and wines (Caleb, Opara, & Witthuhn, 2012; Zaouay, Mena, Garcia-Viguera, & Mars, 2012).

Despite the nutritional and health benefits of consuming pomegranate, there are difficulties in extracting the arils, and this requires adequate knowledge of the fruit mechanical properties such as toughness, firmness, cutting force, and shear strength (Ekrami-Rad, Khazaei, & Khoshtaghaza, 2011). Knowledge of the physical, chemical, and mechanical properties of pomegranate fruit and arils is useful for the design and operation of machines and new processes for harvesting, handling, and postharvest operations (Ekrami-Rad et al., 2011).

Postharvest mechanical tests such as fruit compression simulate static load which is the most common method of deriving stress–strain properties of fruit during handling and storage (Bentini, Caprara, & Martelli, 2009). In the horticultural industry, fruit firmness is used in combination with other maturity indices to identify optimal harvest dates to ensure good storage potential and acceptable sensory quality. Therefore, mechanical properties such as compression and puncture resistance could be important quality indicators of pomegranate, However, there is limited understanding of the effects of temperature on firmness of pomegranate fruit (Johnston, Hewett, Banks, Harker, & Hertog, 2001).

Quality after harvest can greatly be altered during supply chain. Storage temperature, humidity, and duration have a considerable effect on changes in fruit’s quality and mechanical properties (Ekrami-Rad et al., 2011). For instance, Mansouri, Khazaei, and Hassan-Beygy (2011) reported a decrease in firmness during storage period for two Iranian pomegranate cultivars ‘Hondos-e-Yalabad’ and ‘Malas-e-Saveh’. Singh and Reddy (2006) found that temperature and storage time significantly decreased the effect on firmness in ‘Nagpur Mandarin’ oranges at 7°C and 78% relative humidity (RH) for 10 days of storage.

Pomegranate products are new and rapidly increasing in South Africa. Scientific literature on quality attributes, physiological response, and antioxidant capacities of various pomegranate cultivars is voluminous. However, scientific knowledge on mechanical properties of pomegranate fruits is lacking, especially during postharvest storage. Most research on mechanical properties of pomegranates focused mainly on the textural properties of arils. There is a need for a better understanding of relevant mechanical properties of whole fruit and how they relate to storage and processing. This information would be helpful in the design of optimum postharvest handling including packaging, transportation, and storage systems to minimize damage of fruit and maintain quality of arils. The objective of this study was therefore to investigate the effects of storage temperature and duration on postharvest physico-chemical and mechanical properties of pomegranate fruit and arils.

2. Materials and methods

2.1. Plant material and storage conditions

Pomegranate fruits (cv. Wonderful) harvested from several trees on a commercial orchard were obtained from Sonlia Pack-house (33°34′851″S, 19°00′360″E) in Western Cape, South Africa, during the 2012/2013 commercial harvest. Fruits were transported in an air-conditioned vehicle to the Postharvest Technology and Research Laboratory, Stellenbosch University. Fruits were equilibrated at ambient temperature (21 ± 3°C) before being carefully sorted to eliminate any defects. A total of 640 fruits were selected for the determination of physico-chemical and mechanical properties. Fruit samples were packed inside open carton boxes with the following dimensions: width 0.3 m, length 0.4 m, height 0.133 m, and a total of 22 perforations. Fruits were randomly divided into three lots and each fruit lot comprised 200 samples. Another lot of 40 fruits was stored at ambient conditions of 21 ± 3°C and 65 ± 6% RH. Three other lots were stored at each of the following conditions: 5 ± 0.7°C, 7.5 ± 0.3°C and 10 ± 0.5°C with 92 ± 6% RH. Temperature (°C) and RH (%) were monitored on an hourly base using Tiny Tag TV-4500 data loggers (Gemini Data Logger, Sussex, UK).

2.2. Sample preparation and fruit processing

Postharvest physico-chemical and mechanical properties were determined with respect to storage temperature and duration in both ambient and cold storage conditions. Over a period of 5 months, fruits were sampled at 1-month interval. For physico-chemical properties, each fruit was hand-peeled, and 100 g of arils was juiced (without crushing the kernels) using a Liquafresh juice extractor (Mellerware, South Africa) and 10 ml of juice from each fruit was used for chemical analysis. All analyses were performed in triplicate at room temperature.

2.3. Physical properties

2.3.1. Weight loss

Cumulative weight loss for pomegranate fruit was determined for each storage condition; 10 fruit samples of similar size were randomly selected, numbered, and weighed at 1-month intervals. Fruit weight loss was measured with respect to storage period using an electronic scale (Mettler Toledo, Model ML3002E, Switzerland, 0.0001 g accuracy). The loss in weight was calculated as follows:

(1)

where W = cumulative weight loss (%) of fruit; W_i = initial weight (g) of the fruit at the beginning of storage and W_f = final weight (g) of the fruit at the time of sampling during storage. Weight loss was calculated for each storage temperature on 10 individual fruits, and values were presented as mean ± SE.

2.3.2. Aril and peel moisture content

In triplicate, 10 g of arils and 50 g of peel samples were taken into glass petri dishes. Samples were dried in an oven (Prolab, Model OTE 160, South Africa) at 80°C for 24 h. Dried samples were weighed with an electronic balance scale (Mettler Toledo, Model ML3002E, Switzerland, 0.0001 g accuracy). Moisture content was calculated similar to Equation (1), but on a dry-weight bases (db) as follows:

(2)

2.3.3. Peel thickness

Peel thickness was measured using a Vanier caliper (Mitutoyo, Model CD-6 CX, Japan), with 0.01 mm accuracy on opposite sides of 20 pieces of fruit peel. All analyses were performed at room temperature. Peel thickness was measured using 10 randomly selected fruits stored at each temperature, and the average values were reported as mean ± SE.

2.3.4. Color attributes

The color change in pomegranate fruit and arils was measured using the International Commission on Illumination (CIE) L*, a*, b* coordinates with a calibrated Minolta Chroma Meter (Model CR-400/410, Minolta Corp, Osaka, Japan). Peel color measurements were taken along the equatorial axis of each fruit at three marked spots. Similarly, three measurements of aril color were taken in a petri dish. The hue angle (h°) was calculated using Pathare, Opara, and Al-Said (2013):

(3)

Chroma was calculated according to the following equation:

(4)

Results were presented as mean ± SE (n = 10).

2.4. Chemical properties

2.4.1. Titratable acidity, total soluble solids, and pH

Titratable acidity (TA) was measured by diluting 2 ml of fresh juice with 80 ml of distilled water and titrated with 0.1M NaOH to an end point of pH 8.2 using a Metrohm 862 compact titrosampler (Herisau, Switzerland). The results were expressed as percentage of citric acid (% CA). Total soluble solid (TSS, Brix) was measured using a digital refractometer (Atago, Tokyo, Japan). The pH values were determined at room temperature using a calibrated pH meter (Crison, Model 924, Barcelona, Spain). All measurements were made on 10 individual fruit juice samples for each storage temperature, and results were presented as mean ± SE. TSS/TA values were also calculated. To further explore the relationship between TSS and TA, BrimA index was calculated. BrimA index, a variant of the TSS/TA and a criterion for the acceptance of fruit juice, was calculated using TSS – k × TA, where k is the tongue’s sensitivity index normally ranging from 2 to 10 (Fawole & Opara, 2013a; Jordan, Seelye, & McGlone, 2001). To avoid a negative BrimA index, a k value of 2 was used (Fawole & Opara, 2013a).

2.5. Mechanical properties

2.5.1. Fruit puncture resistance test

Fruit texture analyzer (GÜSS-FTA, Model GS, South Africa) was used to measure fruit puncture resistance. A 5 mm cylindrical probe was programmed to puncture 8.9 mm into the fruit at the speed of 10 mm/s on a steel test platform with the stem/calyx axis parallel to the platform. Duplicate tests were performed on opposite sides on the equilateral region of 10 individual fruits for each storage regime. Peak force required to puncture the fruit surface was taken as puncture resistance, and the values were presented as mean ± SE.

2.5.2. Fruit compression test

Fruit compression was performed using a texture profile analyzer XT Plus (Stable MicroSystem Ltd., Godalming, UK) with a 70 x 70 mm, P70 compression platen probe. The texture profile analyzer was calibrated with a 10 kg load cell. The operating conditions for the profile analyzer were as follows: pre-test speed 1.5 mm/s, probe test speed 1 mm/s, post-test speed 10.0 mm/s, compression force 1000 N, and deformation distance 20 mm. A single fruit was placed on a steel test platform, with the stem/calyx axis parallel to the platform, and a force deformation curve was obtained for each test. Two variables, force (N) and distance (mm), were obtained using the force deformation curve and the data were interpreted using texture profile analyzer software Exponent v.4 (Stable MicroSystem Ltd.). The elastic modulus (N/mm²), force (N), toughness (N mm), and bioyield force (N) were calculated by running macro software. The elastic modulus or Young’s modulus could be defined as the initial slope which gives an indication of the fruit’s tendency to deform elastically when a force is applied. The firmness was expressed as the maximum force (N) required to compress the fruit to a distance of 20 mm. The toughness (energy) required to compress the fruit was determined by calculating the area under the force displacement curve. The bioyield point was considered as the force under the prescribed conditions to cause permanent deformation. Fruit compression test was carried out on opposite sides of 10 individual fruits, similar in size for each temperature regime, and values for 20 determinations were presented as mean ± SE.

2.5.3. Fruit cutting test

Texture profile analyzer XT Plus (Stable MicroSystem Ltd.) was used with a blade set knife. For each test, a single pomegranate fruit was positioned with its stem/calyx axis parallel to the platform. The operating conditions for the profile analyzer were as follows: pre-test speed 1 mm/s, probe test speed 1 mm/s, post-test speed 10 mm/s, cutting force 1000 N, and cutting distance 20 mm. The data obtained from the textural profile analyzer were interpreted using software Exponent v.4. The software was used to run macro, which was used to evaluate the cutting force and energy. Fruit cutting test was carried out on opposite side of 10 randomly selected fruits, similar in size for each temperature regime, and values for 20 determinations were expressed as mean ± SE.

2.5.4. Aril compression test

Aril compression test was performed using a texture profile analyzer XT Plus (Stable MicroSystem Ltd.), with a 35 mm diameter cylindrical compression probe. Compression test was performed on individual arils with the following operating conditions: pre-test speed 1.5 mm/s, probe test speed 1 mm/s, post-test speed 10.0 mm/s, compression force 10 N, and compression distance 10 mm (Fawole & Opara, 2013c). The data obtained from the textural analyzer were interpreted using software Exponent v.4 (Stable MicroSystem Ltd.). The software was used to run macro which gave the elastic modulus (N/mm²), rupture force (N), toughness (N mm), and bioyield force (N). Aril compression test was done on 10 randomly selected fruits for each storage regime, and the results presented as mean ± SE of 40 determinations are reported.

2.6. Statistical analysis

Statistical analysis was carried out using Statistica software (Statistical version 10, StatSoft Inc., Tulsa, OK, USA). One-way analysis of variance (ANOVA) was used to evaluate the effects of storage temperature and duration on physico-chemical and mechanical properties. The difference between mean values of parameters was investigated by using Duncan’s multiple range test.

3. Results and discussion

3.1. Physical properties

3.1.1. Weight loss

The percentage cumulative weight loss of pomegranate fruit during storage under ambient (21 ± 3°C 65 ± 6% RH) and cold storage conditions (5°C, 7.5°C, 10°C with 92 ± 5% RH) over 5 months is presented in Figure 1. Pomegranate is highly susceptible to weight loss due to the high porosity of the fruit peel which permits free water vapor movement (Elyatem & Kader, 1984), and the susceptibility could depend on storage conditions. This study showed significant (p < 0.0001) differences in fruit weight loss among the storage temperatures and durations. Weight loss increased with increasing storage temperature and storage duration. Fruit stored at ambient temperature (21°C) for one month lost almost 20% of fruit weight, resulting in more than five folds compared to other storage conditions at the same period. High temperature coupled with low RH at ambient conditions could be responsible for the observed weight loss as such conditions induce high respiration and transpiration in pomegranate fruit (Opara et al., 2008). Weight loss remained below 10% at 7.5°C and 5°C, and no sign of shriveling was observed in fruits even after 2 months of storage. Weight losses obtained after 1 month of storage are comparable with those reported by Elyatem and Kader (1984). The authors reported weight losses of 1.0%, 1.4%, 1.6%, and 2.7% at 0°C, 5°C, 10°C, and 20°C, respectively, after 5 weeks of storage. Interestingly, weight losses in fruits stored at 5°C and 7.5°C did not differ significantly until after 3 months. Only fruits stored at 5°C and 7.5°C lasted for 5 months, with weight loss of 27.67% and 45.67%, respectively. Weight loss obtained at 5°C after 5 months of storage clearly suggests the importance of low temperature and high RH for pomegranate fruit storage. This viewpoint is buttressed by Fawole and Opara (2013b), who reported that both storage temperature and RH had a significant interaction effect on weight loss in ‘Bhagwa’ and ‘Ruby’. Furthermore, fruits stored at 5°C beyond 2 months showed signs of chilling injury which was less than 5% incidence. This was observed when fruit were monitored for physiological disorders.

Figure 1. Cumulative weight loss for pomegranate fruit (Wonderful cultivar) at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months. Different letters on bars mean statistically significant differences (p<0.05).

Figura 1. Pérdida de peso acumulada de la granada (Wonderful cultivar) [almacenada] durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR). Letras diferentes en las barras indican diferencias estadísticamente significativas (p<0,05).

3.1.2. Aril and peel moisture content

Aril and peel moisture content for pomegranate fruit during storage under ambient (21 ± 3°C, 65 ± 6% RH) and cold storage conditions (5°C, 7.5°C, 10°C with 92 ± 5% RH) for up to 5 months of storage is presented in Table 1. Aril moisture content did not change significantly over time under the investigated storage temperatures. However, peel moisture content decreased significantly (p < 0.05) over time. Initial moisture content fruit peel was 78.58% and decreased to 73.08% after 1 month at 21°C. Similarly, the moisture content decreased to 66.16% after 4 months at 10°C and 66.18% and 59.49% after 5 months of storage at 5°C and 7.5°C, respectively. The observed moisture content is an indication that the pomegranate fruit moisture loss was primarily from fruit peel, with negligible moisture loss from aril. This information is important in fruit handling where appropriate storage temperature is required for long-time storage.

Table 1. Peel thickness and moisture content of ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 1. Grosor de la cáscara y contenido de humedad de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

			Moisture content
Duration (months)	Temperature (°C)	Peel thickness (mm)	Aril (%)	Peel (%)
Initial		5.30 ± 0.02ab	81.24 ± 0.34a	78.58 ± 0.48a
1	21	4.20 ± 0.05d	83.49 ± 0.10a	73.08 ± 0.50bc
	10	5.32 ± 0.03a	80.64 ± 0.32a	75.18 ± 0.89ab
	7.5	5.30 ± 0.02ab	81.34 ± 0.20a	76.02 ± 0.35ab
	5	5.30 ± 0.02ab	81.07 ± 0.16a	76.56 ± 0.32ab
2	10	4.61 ± 0.02d	82.45 ± 0.24a	68.29 ± 0.73cde
	7.5	4.57 ± 0.02d	79.74 ± 0.04a	70.60 ± 0.24cd
	5	4.67 ± 0.02cd	83.06 ± 0.14a	73.64 ± 0.31bc
3	10	4.58 ± 0.02cd	80.10 ± 0.41a	68.46 ± 0.20def
	7.5	4.84 ± 0.02cd	80.66 ± 0.12a	70.19 ± 0.30cd
	5	4.57 ± 0.02bc	80.92 ± 0.09a	68.53 ± 0.49def
4	10	3.61 ± 0.02e	81.13 ± 0.07a	66.16 ± 0.44dfg
	7.5	3.87 ± 0.02e	85.11 ± 0.64a	64.55 ± 1.40fg
	5	4.50 ± 0.02d	81.05 ± 0.04a	66.18 ± 0.32defg
5	7.5	3.66 ± 0.02e	82.72 ± 0.26a	59.49 ± 0.59g
	5	3.69 ± 0.02e	81.69 ± 0.16a	65.13 ± 0.17efg
p-value		<0.0001	0.99945	<0.0001

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

3.1.3. Peel thickness

There were decreases in peel thickness at all the investigated storage conditions over time (Table 1). After 1 month of storage, peel thickness decreased significantly (p < 0.05) at 21°C, whereas the decrease was not significant at 5°C, 7.5°C, and 10°C. Drastic decrease in peel thickness at ambient temperature may be due to low RH coupled with high temperature. Peel thickness gradually decreased from the initial 5.3 mm to 3.61 mm after 4 months at 10°C and to 3.69 mm and 3.66 mm after 5 months of storage at 5°C and 7.5°C, respectively. The decrease in peel thickness may be attributed to moisture loss from fruit peel as storage period progressed. However, moisture loss was minimized at 5°C compared to other storage regimes. This study provides basic information on the effects of temperature and duration on fruit peel, which could be used for potential applications in the construction of aril extraction equipment.

3.1.4. Peel and aril color

Color of pomegranate fruit is an important quality attribute affecting marketability, consumer’s acceptance, and commercial value (Gil, Sanchez, Marin, & Artes, 1996). The color attributes of whole fruit (Table 2) and arils (Table 3) changed significantly (p < 0.05) at all the investigated storage conditions. Increase in peel color of fruit stored at 5°C was obvious during the first 3 months of storage. The intense coloration was evident by increases in the CIE a* and C* values as well as by decrease in the h°. The increase in C* values could be as a result of biosynthesis and accumulation of anthocyanin pigments in the peel, resulting in intense red coloration (Gil, García‐Viguera, Artés, & Tomás‐Barberán, 1995). However, fruit external appearance deteriorated after 3 months up till the end of the storage trials (5 months), possibly as a result of breakdown or browning of the husk. In contrast, aril color declined at varying degrees under the investigated storage temperatures throughout the storage period (Table 2). Overall, the results indicated that the color of fruit peel and aril was better maintained at 5°C for between 2 and 3 months, when red coloration (a*) and intensity (C*) for peel and arils were considerably higher than the perceived fruit color at harvest.

Table 2. Peel color dynamics of ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 2. Dinámicas del color de la cáscara de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	L*	a*	C*	h°
Initial		48.27 ± 0.24ef	39.81 ± 0.21bc	47.09 ± 0.12cd	32.02 ± 0.19cdef
1	21	42.46 ± 0.14g	38.75 ± 0.11cd	44.10 ± 0.11ef	28.27 ± 0.12f
	10	48.38 ± 0.28ef	39.56 ± 0.25bc	46.47 ± 0.15de	31.42 ± 0.26cdef
	7.5	46.75 ± 0.25fg	40.87 ± 0.18bc	47.23 ± 0.13cd	29.72 ± 0.23ef
	5	45.86 ± 0.23fg	41.91 ± 0.13bc	47.80 ± 0.13bcd	28.29 ± 0.18f
2	10	64.15 ± 0.37a	39.27 ± 0.32c	47.30 ± 0.25cd	33.53 ± 0.33bcde
	7.5	61.38 ± 0.34ab	42.32 ± 0.22bc	49.59 ± 0.15bc	30.86 ± 0.29cef
	5	58.41 ± 0.29bc	46.13 ± 0.17a	53.57 ± 0.15a	30.03 ± 0.22ef
3	10	56.45 ± 0.36cd	33.27 ± 0.24ef	41.25 ± 0.20fgh	35.60 ± 0.32abc
	7.5	55.59 ± 0.31cd	41.02 ± 0.22bc	49.08 ± 0.13bcd	32.59 ± 0.31bcdef
	5	51.91 ± 0.27de	43.27 ± 0.17ab	50.54 ± 0.15b	30.40 ± 0.24bcdef
4	10	46.99 ± 0.26efg	29.66 ± 0.21g	38.63 ± 0.17h	39.24 ± 0.30a
	7.5	46.23 ± 0.27fg	33.42 ± 0.16ef	41.57 ± 0.14fg	35.57 ± 0.29abc
	5	44.26 ± 0.22fg	35.83 ± 0.15de	43.25 ± 0.13f	32.34 ± 0.15bcdef
5	7.5	44.67 ± 0.23fg	30.84 ± 0.17fg	39.82 ± 0.12gh	37.30 ± 0.32ab
	5	42.88 ± 0.22g	34.97 ± 0.17e	42.90 ± 0.14f	35.45 ± 0.31abcd
p-value		<0.0001	<0.0001	<0.0001	<0.0001

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

Table 3. Aril color dynamics of ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 3. Dinámicas del color del arilo de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	L*	a*	C*	h°
Initial		25.83 ± 0.28abc	23.94 ± 0.21abc	26.68 ± 0.23a	25.90 ± 0.10ab
1	21	18.63 ± 0.27efg	20.40 ± 0.21def	22.72 ± 0.24bcd	25.76 ± 0.16ab
	10	24.82 ± 0.34abcd	22.12 ± 0.19bcd	24.98 ± 0.21ab	26.94 ± 0.19a
	7.5	23.17 ± 0.35bce	18.75 ± 0.19ef	21.27 ± 0.19cde	27.02 ± 0.30a
	5	19.24 ± 0.29efg	21.08 ± 0.17cdef	23.40 ± 0.19bc	25.03 ± 0.23ab
2	10	26.05 ± 0.31abc	24.91 ± 0.18ab	27.23 ± 0.21a	23.03 ± 0.15bcd
	7.5	28.50 ± 0.36a	24.59 ± 0.19abc	25.40 ± 0.20ab	21.08 ± 0.20cde
	5	26.84 ± 0.39ab	25.27 ± 0.10a	27.34 ± 0.11a	22.31 ± 0.08bcd
3	10	24.24 ± 0.30abcd	21.36 ± 0.19dce	23.48 ± 0.21bc	23.83 ± 0.20abc
	7.5	20.89 ± 0.29def	18.63 ± 0.15ef	19.86 ± 0.18def	18.38 ± 0.22e
	5	21.81 ± 0.19cdef	21.93 ± 0.14bcd	23.11 ± 0.15bcd	17.90 ± 0.10e
4	10	14.86 ± 0.21g	17.97 ± 0.16fg	19.56 ± 0.18ef	22.30 ± 0.17bd
	7.5	15.74 ± 0.21g	19.04 ± 0.15def	20.47 ± 0.17cef	20.98 ± 0.12cde
	5	15.68 ± 0.15g	19.56 ± 0.19def	20.95 ± 0.21cef	19.85 ± 0.15de
5	7.5	17.71 ± 0.21fg	15.69 ± 0.21g	17.64 ± 0.22f	25.06 ± 0.50ab
	5	19.19 ± 0.26efg	19.10 ± 0.16def	20.62 ± 0.15cdef	20.31 ± 0.18cde
p-value		<0.0001	<0.0001	<0.0001	<0.0001

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

3.2. Chemical properties

Chemical parameters like TSS, TA, and TSS/TA have been used to describe taste (flavor) with regard to the sweetness and acidity; it has been used as a quality criterion for the formulation of pomegranate products and its juice (Al-Said et al., 2009). As shown in Table 4, there were significant differences (p < 0.05) in the juice chemical properties at different storage conditions. The lowest TSS (°Brix) content was recorded at commercial harvest (week 0). TSS increased significantly (p < 0.05) during storage at the investigated temperature regimes. For instance, after a 1-month storage, TSS increased from 13 Brix to 16.22 Brix, 15.36 Brix, 14.84 Brix, and 14.35 Brix at 5°C, 7.5°C, 10°C, and 21°C, respectively. The TSS level remained relatively steady up till the end of the experiment, with the TSS content being 16.22 Brix in fruits stored at 5°C for 5 months (Table 4). The possible reason for the observed increase in TSS contents could be as a result of moisture loss, leading to concentration of sugars inside the fruit. In contrast to our present study, Artés, Tudela, and Gil’s (1998) and Kader, Chordas, and Elyatem’s (1984) previous study done on other pomegranate cultivars showed a decline in TSS as storage period progressed (Artés et al., 1998; Kader et al., 1984). The decrease in TSS content by these authors during storage could be attributed to degradation of sugars over time. Overall, storage temperature of 5°C would have the best keeping potential for the investigated cultivar in terms of TSS.

Table 4. Chemical attributes of ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 4. Atributos químicos de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	TSS	TA	pH	TSS:TA	BrimA
Initial		13.38 ± 0.11g	1.37 ± 0.04abc	3.09 ± 0.02abc	10.59 ± 0.33f	10.64 ± 0.16e
1	21	14.35 ± 0.13cdef	1.03 ± 0.03ef	3.11 ± 0.01a	14.75 ± 0.32f	12.30 ± 0.13de
	10	14.84 ± 0.12ef	1.59 ± 0.04a	3.04 ± 0.01ef	10.16 ± 0.37bde	10.64 ± 0.15cd
	7.5	15.36 ± 0.11abcde	0.96 ± 0.02ef	3.22 ± 0.01ef	16.80 ± 0.42abc	13.45 ± 0.12abc
	5	16.22 ± 0.13a	0.95 ± 0.03ef	3.37 ± 0.02ef	18.04 ± 0.51ab	14.33 ± 0.11a
2	10	15.80 ± 0.07abc	1.42 ± 0.03ab	3.02 ± 0.01ab	11.55 ± 0.23ef	12.96 ± 0.08bc
	7.5	15.95 ± 0.12ab	1.16 ± 0.03bcde	3.35 ± 0.01bcde	14.32 ± 0.33cde	13.62 ± 0.17ab
	5	15.51 ± 0.08abcd	1.01 ± 0.02ef	3.17 ± 0.01ef	14.69 ± 0.25bcde	13.64 ± 0.08ab
3	10	15.42 ± 0.12abcde	1.43 ± 0.04ab	3.19 ± 0.02ab	11.50 ± 0.33ef	12.56 ± 0.13bcd
	7.5	15.84 ± 0.08abc	1.19 ± 0.03bcde	3.29 ± 0.01bcde	14.14 ± 0.39cde	13.46 ± 0.12abc
	5	15.84 ± 0.08abc	1.09 ± 0.02def	3.42 ± 0.01def	14.93 ± 0.26bcde	13.24 ± 0.11ab
4	10	16.02 ± 0.13ab	1.31 ± 0.03bcd	3.18 ± 0.01bcd	12.88 ± 0.36def	11.66 ± 0.17abc
	7.5	14.71 ± 0.11def	1.01 ± 0.02ef	3.53 ± 0.01ef	15.19 ± 0.31bcd	12.71 ± 0.12bcd
	5	16.20 ± 0.10a	0.87 ± 0.01f	3.56 ± 0.01f	19.03 ± 0.34a	12.74 ± 0.40bcd
5	7.5	14.12 ± 0.11fg	0.94 ± 0.02ef	3.50 ± 0.01ef	15.63 ± 0.36bcd	12.23 ± 0.12bc
	5	15.07 ± 0.09bcdef	1.11 ± 0.02cdf	3.49 ± 0.01cdef	14.07 ± 0.33cde	12.85 ± 0.12bcd
p-value		<0.0001	<0.0001	<0.0001	<0.0001	<0.0001

Notes: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. TSS, total soluble solids (Brix); TA, titratable acidity (% citric acid). Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

TA significantly (p < 0.05) decreased at all storage conditions, with the exception of 10°C which significantly (p < 0.05) increased at 1 month of storage and gradually decreased with storage duration. This increase in TA may be attributed to water loss which increases with storage temperature. Furthermore, the significant (p < 0.05) decrease at a higher temperature of 21°C may be attributed to low RH and the rapid breakdown of organic acids. Increases in TA levels during storage have previously been reported by Gil et al. (1996) for the Spanish ‘Mollar de Elche’ cultivar. On the contrary, several authors have reported a decline in TA levels for pomegranate fruits (Artes, Villaescusa, & Tudela, 2000; Fawole & Opara, 2013b); the storage behavior of TA would differ depending on the cultivar, growing region, and storage conditions (Gil et al., 1996; Martínez et al., 2012). TA for the investigated cultivar ranged during storage between 0.87 and 1.59 (% CA). The high variability in TA values at different temperatures could possibly be due to moisture loss resulting in increased organic acid concentration with increase in temperatures. The pH values increased as storage period progressed at all storage regimes. The increase in pH was accompanied by a decline in acidity levels. Similarly, Fawole and Opara (2013b) observed an increase in pH values for two South African grown cultivars ‘Bhagwa’ and ‘Ruby’. These authors reported that the interactions between storage temperatures and durations played a significant role on fruit pH for ‘Ruby’.

As a result of the changes in TSS and TA contents, TSS/TA ratio increased from 10.59 to 19.03 during storage, with significant changes observed at different storage temperatures. The calculated TSS/TA values in the present study are similar to those reported by Ben-Arie, Segal, and Guelfat-Reich (1984), with TSS/TA values ranging from 11 to 16 for ‘Wonderful’ cultivar.

In a quest to exploring chemical changes related to flavor, we used BrimA index adopted from Jordan et al. (2001). This index allows for small amounts of acid than sugar to make the same numerical changes to BrimA index as observed in the present study (Table 4). BrimA increased from 10.64 at harvest to 14.33, 13.62, 12.96, and 12.30 for 5°C, 7.5°C, 10°C, and 21°C, respectively, during storage. The increase in BrimA could be related to the decrease in TA levels occurring during storage. Our result is contrary to Fawole and Opara (2013b), who reported that significant interactions were observed between storage temperatures and storage durations resulting in a decrease in BrimA index for ‘Ruby’ cultivar stored at 5°C, 7°C, 10°C, and 21°C for 4 months of storage. Overall, storage temperature of 5°C for 2 months seems to be best suitable for the calculation of BrimA compared to other storage regimes.

3.3. Mechanical properties

Ambient conditions (21 ± 3°C and 65 ± 6% RH) were not studied as storage of fruits up to 1 month resulted in decay and were limited.

3.3.1. Puncture resistance

Fruit puncture resistance increased in fruits stored at all storage regimes in the first month of storage, indicating hardening of the peel (Table 5). The increase in puncture resistance was more pronounced under 10°C (138.64 N) than that under 5°C (130.32 N) and 7.5°C (133.52 N), respectively. Increase in puncture resistance could be due to moisture loss from the fruit which resulted in the hardening of the pomegranate peel. However, after 1 month of storage, a decrease in puncture resistance was observed. The overall decreases in puncture resistance with prolonged storage duration suggest that softening of fruit and its arils occurs during storage. Similar results were reported by Mansouri et al. (2011), who showed the loss of puncture resistance in fruit during storage at 5°C for 30 days. This fruit property could be used with several other quality indices to predict fruit firmness for optimum storage potential.

Table 5. Puncture resistance for ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 5. Resistencia a la perforación de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	Force (N)
Initial		127.94 ± 1.19ab
1	10	138.64 ± 1.29a
	7.5	133.52 ± 1.45a
	5	130.29 ± 1.36ab
2	10	126.83 ± 0.98ab
	7.5	122.66 ± 1.01abc
	5	114.00 ± 1.29bcd
3	10	122.00 ± 1.19abc
	7.5	112.03 ± 1.54bcd
	5	109.36 ± 0.77cde
4	10	97.50 ± 1.13def
	7.5	104.38 ± 1.28def
	5	95.69 ± 0.97ef
5	7.5	97.50 ± 1.13def
	5	86.25 ± 1.08f
p-value		<0.0001

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

3.3.2. Fruit compression

Fruit compression results of pomegranate fruit in cold storage conditions is presented in Table 6. There was a significant (p < 0.05) difference in the force required to compress fruit at different temperatures. The force required to compress fruit decreased significantly (p < 0.05) from harvest (295.24 N) and continued to decline with extended storage duration, resulting in the lowest observed force at 5°C (162.64 N) for 5 months. This observation indicates that extended storage duration results in a decline in fruit firmness. The decrease in firmness may be due to the loss in cell wall integrity of the pomegranate arils (Ekrami-Rad et al., 2011). Another reason for the significant decrease for the Wonderful fruit stored at 5°C for 5 months of storage could be as a result of chilling injury, which ultimately leads to loss of cell-wall integrity in pomegranate (Elyatem & Kader, 1984). Our results with regard to fruit firmness are in agreement with Ekrami-Rad et al. (2011), who reported a reduction in firmness for ‘Wonderful’ stored at 5°C for 5 months. Similarly, the influence of temperature and storage duration on fruit toughness (energy) was significantly (p < 0.05) evident, where the amount of energy to compress fruit was reduced with increasing storage duration. Furthermore, Holt (1970) reported that several factors affect fruit compression test results; this may depend on the mechanical strength of the skin, firmness of the flesh, juice viscosity, and size of the fruit.

Table 6. Fruit compression property for ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 6. Características de compresión de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	Elastic modulus (N/mm)	Firmness (N)	Toughness (N mm)	Bioyield (N)
Initial		355.77 ± 12.18a	295.24 ± 2.28a	1236.12 ± 15.28a	32.81 ± 0.52a
1	10	315.91 ± 10.67a	250.39 ± 2.57bc	1111.68 ± 12.39ab	26.34 ± 0.26bc
	7.5	254.22 ± 12.71a	233.65 ± 12.52bcd	1042.40 ± 55.58bc	23.55 ± 1.32bcdef
	5	221.95 ± 9.57a	231.15 ± 2.27cd	977.76 ± 11.33bcd	23.26 ± 0.23bcdef
2	10	277.42 ± 9.49a	255.99 ± 2.05ab	1065.65 ± 10.69ab	27.66 ± 0.30b
	7.5	231.85 ± 12.30a	211.18 ± 3.93de	825.27 ± 20.41d	21.68 ± 0.31cdef
	5	252.41 ± 12.21a	204.47 ± 2.21de	834.76 ± 13.10d	21.53 ± 0.31cf
3	10	321.02 ± 15.30a	232.67 ± 2.92bcd	960.79 ± 13.91bcd	24.83 ± 0.45bcde
	7.5	310.25 ± 10.17a	207.46 ± 2.18de	893.18 ± 9.09cd	20.75 ± 0.22def
	5	302.96 ± 10.92a	189.80 ± 2.41ef	795.51 ± 11.63d	19.00 ± 0.24f
4	10	360.39 ± 19.65a	220.89 ± 3.43cde	882.54 ± 13.60cd	24.20 ± 0.53bcdef
	7.5	329.88 ± 12.62a	213.05 ± 2.34de	868.25 ± 9.89cd	23.41 ± 0.49bcdef
	5	308.76 ± 14.42a	200.16 ± 2.66de	837.91 ± 12.03d	20.35 ± 0.26dcdef
5	7.5	379.79 ± 18.70a	228.20 ± 2.66cd	870.93 ± 13.07cd	25.30 ± 0.40bcd
	5	192.68 ± 9.52a	162.64 ± 1.78f	574.07 ± 10.14e	19.42 ± 0.39ef
p-value		0.05463	<0.0001	<0.0001	<0.0001

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test.

The bioyield point declined at all the investigated storage temperatures when compared with fruit at harvest (32.81 N). However, the decline was not significant (p > 0.05) amongst majority of storage temperatures but rather affected by storage duration. A similar trend was reported by Singh and Reddy (2006) for oranges. The reduction in bioyield demonstrates increased deformability of fruit to compression test as storage period progressed. The Young’s modulus did not significantly (p > 0.05) change during temperature or storage duration. As observed with the investigated cultivar, the reduction of Young’s modulus at 5°C for 5 months showed that fruit moisture in fruit peel is still retained. Overall, the best suitable temperature for fruit firmness would be at 5°C for the investigated cultivar.

3.3.3. Fruit cutting test

The cutting force and energy of pomegranate fruit in cold storage conditions are presented in Table 7. Cutting force did not differ significantly (p < 0.05) as a result of storage temperature, particularly between 1 and 2 months, but rather declined after harvest (229.56 N). Although, the influence of temperature and storage duration was significantly (p < 0.05) apparent on the cutting energy. Moreover, the energy required to cut pomegranate fruit declined and gave a similar trend observed by cutting force. The decrease in cutting force may be attributed to peel thinning and gradual changes to the inner portions of the fruit occurring during storage, leading to softening (Ekrami-Rad et al., 2011). Similar results were reported by Ekrami-Rad et al. (2011), who showed a decrease in cutting force and energy during storage ‘Wonderful’ at 5°C for 5 months.

Table 7. Fruit cutting test for ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 7. Prueba de corte de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	Force (N)	Toughness (N mm)
Initial	–	229.56 ± 3.08a	1425.43 ± 29.55abcd
1	10	203.29 ± 2.08abc	1269.95 ± 17.94bcde
	7.5	193.69 ± 2.29abc	1108.50 ± 16.56de
	5	203.82 ± 3.20abc	1535.42 ± 38.89abc
2	10	191.15 ± 2.41bc	1272.48 ± 27.20bcde
	7.5	153.81 ± 2.33abc	909.21 ± 23.27de
	5	194.71 ± 2.63abc	1433.98 ± 26.83abcd
3	10	191.75 ± 1.81bc	1433.98 ± 25.92abcd
	7.5	185.41 ± 2.06bcd	1152.08 ± 15.98cde
	5	190.74 ± 3.05cd	1343.88 ± 36.07bcde
4	10	200.34 ± 2.26d	1113.32 ± 21.10e
	7.5	184.66 ± 1.66bcd	1297.75 ± 21.25bcd
	5	222.30 ± 2.62ab	1709.68 ± 30.14a
5	7.5	198.53 ± 2.93abc	1549.95 ± 30.18ab
	5	201.13 ± 1.56abc	1459.37 ± 35.03abcd
p-value		0.0512	0.00025

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

3.3.4. Aril compression test

The textural property is an important quality attribute in the pomegranate industry (Fawole & Opara, 2013c). The results obtained showed that aril hardness, elastic modulus, energy, and bioyield changed significantly during storage (Table 8). After 2 months, aril hardness did not differ significantly amongst storage temperatures. Although, aril hardness showed a significant (p < 0.0001) decreasing trend with extended storage duration, resulting in the lowest force being observed at 10°C (112.29 N) and 7.5°C (112.22 N) for 4 months. The decrease in aril hardness has been attributed to loss in cell-wall integrity of pomegranate arils (Ekrami-Rad et al., 2011). The reduction in the Young’s modulus demonstrates the increasing deformability of fruit arils with increase in storage temperature and duration. Similarly, it was observed that the energy required to compress aril declined with a reduction in aril hardness. This behavior for pomegranate aril demonstrates a tendency for elasticity to decrease with storage temperature and period. Bioyield showed slight variation; however, no significant difference was observed for 7.5°C and 10°C for 4 and 3 months of storage, respectively. Similar results were reported by Fawole and Opara (2013c), who showed a loss of firmness in arils during fruit storage at 5°C for 6 weeks with a shelf life period of 5 days at 20°C.

Table 8. Aril compression property of ‘Wonderful’ fruit stored at 21°C (65% RH), 10°C (92% RH), 7.5°C (92% RH), and 5°C (92% RH) for 5 months.

Tabla 8. Características de compresión del arilo de la fruta “Wonderful” almacenada durante cinco meses a: 21°C (65% HR), 10°C (92% HR), 7,5°C (92% HR), y 5°C (92% HR).

Duration (months)	Temperature (°C)	Elastic modulus (N/mm)	Hardness (N)	Toughness (N mm)	Bioyield (N)
Initial		4.15 ± 0.10a	127.30 ± 0.97a	157.46 ± 1.51a	18.76 ± 0.14ab
1	10	3.18 ± 0.08bcd	125.80 ± 0.84a	154.82 ± 1.19ab	18.67 ± 0.11ab
	7.5	2.55 ± 0.08def	121.03 ± 0.68abcd	146.45 ± 1.13abcdef	17.66 ± 0.15abc
	5	4.52 ± 0.08a	123.24 ± 0.93abc	147.28 ± 1.10abcdef	18.69 ± 0.13ab
2	10	4.38 ± 0.10a	124.35 ± 0.98ab	156.21 ± 1.15a	18.15 ± 0.13abc
	7.5	2.80 ± 0.08cdf	124.41 ± 0.71ab	148.38 ± 0.84abcde	18.60 ± 0.12ab
	5	3.77 ± 0.10ab	123.62 ± 0.54ab	149.20 ± 0.71abcd	18.10 ± 0.09abc
3	10	2.16 ± 0.08ef	117.26 ± 0.67be	136.23 ± 0.79ef	18.24 ± 0.10ac
	7.5	2.76 ± 0.09df	119.52 ± 0.72ae	143.02 ± 1.12bf	18.22 ± 0.12ac
	5	2.94 ± 0.08bdf	117.26 ± 0.90be	142.22 ± 1.60cf	18.65 ± 0.16ab
4	10	3.07 ± 0.05bde	112.29 ± 0.38e	139.41 ± 0.62df	17.50 ± 0.06ac
	7.5	3.20 ± 0.07bd	112.22 ± 0.79e	135.56 ± 1.10f	16.91 ± 0.14c
	5	4.01 ± 0.10abc	119.93 ± 0.73ab	148.18 ± 1.35abc	18.43 ± 0.13a
5	7.5	2.12 ± 0.03f	113.20 ± 0.29de	140.84 ± 0.52df	17.01 ± 0.06c
	5	2.70 ± 0.59def	115.37 ± 020ce	132.01 ± 0.78bf	17.66 ± 0.13bc
p-value		<0.0001	<0.0001	<0.0001	<0.0001

Note: Values are presented as mean ± SE. Mean values in the same column followed by different letter(s) indicate significant difference (p < 0.05) according to Duncan’s multiple range test. Storage trials for fruits stored at 21°C and 10°C were discontinued after 1 month and 4 months, respectively, due to complete fruit loss to decay.

4. Conclusions

Changes in physico-chemical and mechanical properties of pomegranate fruit Wonderful cultivar at different storage temperatures were investigated, which would provide useful information regarding quality changes during transportation and storage. It can be concluded that the investigated cultivar should be stored at low temperatures (5°C) and high (>92%) RH in other to minimize weight loss, slow down chemical depreciation, and maintain overall fruit quality. Our study showed that weight loss, color attributes, chemical attributes, and textural quality of the fruit can be optimally maintained at 5°C for 2 months of storage. These findings may be of value for the development of optimal storage conditions for handling and processing of pomegranate fruit for food and industrial use.