Determination of Physico-chemical Properties of Aonla (Emblica officinalis Gaerth) Fruits among Different Populations in Garhwal Himalaya

ABSTRACT

The present investigation was conducted to evaluate the variation in nutritive contents in wild-growing fruits of Emblica officinalis. Fruits of E. officinalis were collected from twenty-eight naturally growing populations in different parts of Garhwal-Himalaya, Uttarakhand, India. Several fruit properties including number of fruits kg⁻¹, fruit weight, fruit diameter, fruit length, fruit volume, pulp weight, pulp:stone ratio, specific gravity, moisture percent, total soluble solid, malic acid, citric acid, tartaric acid, vitamin C, and sugar contents were analyzed to observe the variations among different populations. The results of the study revealed that the average fruit weight varied significantly (P< .05) from 2.70 to 13.61 g. Total soluble solids, malic acid, citric acid, tartaric acid, and vitamin C were found ranged between 10.68 and 21.42 °Brix; 1.43 and 3.78%; 1.37 and 3.61%; 3.21 and 8.46% and 191.13 and 495.21 mg 100 g¹, respectively). Fruit weight was the most variable parameter among the physical characteristics. Vitamin C and organic acid contents were highly variable among different populations. Latitude and longitude had significant inverse relationship with organic acids. However, altitude did not affect the physico-chemical properties. The variability in the studied traits appeared to be geographically structured and would be mainly controlled genetically. The natural variation in wild fruit populations had given great opportunity to understand the variability in physical and chemical properties of fruit and response to biotic and abiotic stresses.

KEYWORDS:

• Anola
• Emblica officinalis
• fruit composition
• genetic resources
• Himalaya
• India
• pomology

Introduction

Aonla (Emblica officinalis Gaerth) is a deciduous tree species (Euphorbiaceae), native to India (Gaur, 1999). It is known as Indian gooseberry that occurs naturally in tropical South-East Asia, particularly in the Central and Southern India (Firminger, 1947). E. officinalis is also common in the mixed deciduous forests of India up to 1,350 meters above sea level (m.a.s.l) in the hills of Himalaya (Gaur, 1999). The fruit of E. officinalis is considered as ‘wonder fruit for health’ because of its unique qualities, namely astringent, cooling anodyne, carminative, digestive, stomachic, laxative, aphrodisiac, diuretic, antipyretic, and trichogenous and also useful in the treatment of many diseases including diabetes, cough, asthma, bronchitis, headache, ophthalmic disorder, dyspepsia, colic, flatulence, skin diseases, leprosy, jaundice, scurvy, diarrhea, diabetes, and grayness of hair (Anonymous, 1952). It is also reported to have anticancer properties (Ngamkitidechakul et al., 2010). The vitamin C content in aonla fruit is 500–600 mg100 g⁻¹, which is next to that of Barbados cherry (Malpighia glabra L) (Shankar, 1969). Aonla fruits have sour and astringent test, which is consumed as a raw, used for making pickles, juices, jam, cheese, candy, powder, beverages, laddoo, burfee, and chutney (Mudit et al., 2018). Organic acids are effective on taste and aroma in fruits. The ratio of these compounds affects whether the fruits are sweet or sour. In addition, these compounds affect some enzyme activities and react with other biochemical compounds and take part in many physiological events in fruits (Aytül et al., 2019; Gündoğdu, 2019). Aonla is regarded as sacred by Hindus and has great mythological significance. Aonla is a nutritious fruit at low cost. The species is capable of yielding fruits under adverse conditions on marginal land (Gaur, 1999). This will create a very good chance in employment generation, rehabilitation of marginal and wastelands, promotion of large-scale health improvement cottage industries of the people in the tropical to subtropical region of India including Pakistan, Sri Lanka, South-East Asia, China, and Malaysia. The fruits require careful attention during processing due to perishable nature and lack of storage facilities (local fruit markets) make this fruit underutilized among farmers. Growers are compelled to sell the produce on the price fixed by traders. Poor infrastructure and low profit to farmers leads to increasing distress attention to this crop. Despite being an underutilized fruit, aonla has enormous potential in the world market. Therefore, it is necessary to highlight the nutritional properties of wild-growing population of E. officinalis fruits.

The study of nutritional quality and bioactive contents in aonla which grows in different parts of Garhwal Himalaya is not available so far. Therefore, this study was mainly focused on E. officinalis in Garhwal Himalaya, Uttarakhand, India, to understand the variation in physical properties and chemical composition of fruits among different populations growing wild. The study would be helpful to recommend the elite germplasm for in-situ conservation and various afforestation and reforestation programs.

Materials and Methods

Mature fruits of E. officinalis were collected from twenty-eight different natural populations of Garhwal Himalaya, India. The geographical location of different populations (hereinafter referred as seed source) ranged from 29°55ʹ01.61” to 30°24ʹ15.43”N latitude and 78°30ʹ09.50” to 79°19ʹ55.17”E longitude. The altitude of the entire range of seed sources varied from 446 to 1,620 m.a.s.l. (Table1).

Table 1. Geographical description of fruit collection sites in Garhwal Himalayan region, India

S.N.	Population	District	Altitude (m asl)	Latitude	Longitude
1	Kaudiyala	Tehri	446	30°04ʹ27.92”N	78°30ʹ09.50”E
2	Devprayag	Tehri	510	30°08ʹ44.93”N	78°36ʹ00.71”E
3	Satpuli	Pauri	630	29°55ʹ01.61”N	78°42ʹ36.88”E
4	Kaliyasauar	Pauri	665	30°15ʹ27.96”N	78°52ʹ50.16”E
5	Dangchaura	Tehri	692	30°16ʹ00.10”N	78°42ʹ59.81”E
6	Chauki	Rudraparyag	742	30°20ʹ43.96”N	78°58ʹ31.23”E
7	Khandah	Pauri	742	30°11ʹ36.45”N	78°46ʹ43.14”E
8	Farashu	Pauri	755	30°14ʹ25.77”N	78°51ʹ14.94”E
9	Khankhara	Rudraparyag	758	30°14ʹ35.76”N	78°55ʹ01.16”E
10	Pathisain	Pauri	759	29°58ʹ49.99”N	78°46ʹ48.34”E
11	Gauchar	Chamoli	790	30°17ʹ15.22”N	79°09ʹ04.59”E
12	Rudraparyag	Rudraparyag	798	30°17ʹ32.05”N	78°59ʹ22.42”E
13	Karnaparyag	Chamoli	864	30°15ʹ32.06”N	79°13ʹ09.01”E
14	Augastmuni	Rudraparyag	872	30°23ʹ26.37”N	79°01ʹ38.76”E
15	Khola	Pauri	919	30°12ʹ46.45”N	78°47ʹ17.98”E
16	Pabau	Pauri	1035	30°06ʹ11.41”N	78°53ʹ09.16”E
17	Chamoli	Chamoli	1062	30°24ʹ15.43”N	79°19ʹ55.17”E
18	Hisriyakhal	Tehri	1119	30°15ʹ36.65”N	78°40ʹ03.83”E
19	Naugad	Tehri	1171	30°16ʹ27.27”N	78°50ʹ29.23”E
20	Bughani	Pauri	1254	30°12ʹ41.87”N	78°51ʹ14.86”E
21	Paukhal	Tehri	1263	30°21ʹ43.86”N	78°36ʹ43.48”E
22	Jakheti	Pauri	1320	30°02ʹ11.54”N	78°47ʹ51.29”E
23	Silkakhal	Tehri	1426	30°16ʹ15.85”N	78°47ʹ25.50”E
24	Parsundakhal	Pauri	1486	30°04ʹ40.49”N	78°46ʹ31.60”E
25	Maikoti	Rudraparyag	1540	30°20ʹ27.40”N	78°59ʹ57.55”E
26	Kholachauri	Pauri	1552	30°09ʹ20.95”N	78°40ʹ40.14”E
27	Pauri	Pauri	1563	30°08ʹ44.26”N	78°46ʹ44.12”E
28	Jakholi	Rudraparyag	1620	30°23ʹ32.48”N	78°57ʹ08.65”E

Fruits were collected from 10 randomly selected healthy and mature standing trees in each seed source. Selected trees were growing 100 m apart from the nearest neighbor to avoid narrowing down the variation due to relatedness (Schmidt, 2000). About 5 kg fruits were collected from each tree and brought to the laboratory for composite sampling. The samples collected from each seed source were placed in a cotton bag for minimum losses and respiration during transportation, assigned an accession number (name of place), and stored in waterproof plastic container in a cool incubator (5°C) until further analysis.

Five replicates, each of 20 fruits of each seed source were chosen to record fruit weight and pulp weight with an electronic top pan balance (model Z-400) and expressed in gm. Further, the five replications of every seed source (each consisting of twenty fruits) were selected to measure fruit diameter and fruit length in cm with the help of micrometer (Besto). The fruit length was taken from the apex to the stem end. The volume of twenty randomly selected fruits in five replicates was taken by water displacement method using a measuring cylinder and the average fruit volume was expressed in ml.

The pulp thickness (five replicates with 20 fruits each) was measured by cutting the fruits from the middle into two segments and recorded with the help of micrometer (Besto). Further, the fruits were scrapped with the help of stainless steel knife to separate pulp and stone. Pulp and stone were weighed separately and the average pulp:stone ratio was calculated by simple division. The specific gravity of fruits for each seed source was calculated using the formula.

Specific gravity$=\frac{\mathrm{W}}{\mathrm{V}}$

W= Average weight of fruit in gm.

V= Average volume of fruit in ml.

The moisture content (%) of fruits of each seed source was determined on a fresh weight basis by drying the fruits at 103 ± 3°C as per ISTA (ISTA, 1999) rules. For determination of total soluble solids a composite sample (five replicate with 20 fruits) of each seed source was taken and fruit juice was obtained with the help of juice extractor at room temperature (20°C). Few drops of extract were taken from each replicate in hand refractometer and then it was observed in °Brix.

The acidity (malic/citric/tartaric) of fruits was estimated by titrating the fruit juice (10 mL juice was taken against standard N/10 sodium hydroxide solution) using phenolphthalein indicator. The appearance of light pink color was marked as the end point. This was expressed in terms of percentage by using the formula given by (AOAC, 1975). Vitamin C content was estimated by using 2, 6-Dichlorophenol indophenol (DCPIP) visual titration method. This method involves reduction of 2,6-Dichlorophenol indophenol (standard dye) to deep blue in alkaline solution and a pink end pointed in ascorbic acid. Ascorbic acid in terms of 100 mg100 g-1 pulp weight was calculated following the method of Ranganna (2004).

Total sugar was determined by the method of McCready et al. (1950). About 10 mL of fruit juice was homogenized with 10 ml of 80% boiling ethyl alcohol. The homogenized juice was centrifuged at 3,000 rpm for 10 min. The supernatant was used to estimate soluble sugar. About 0.1 ml supernatant was taken in dry test tube to which was added 0.9 ml distilled water and 4 ml of cold anthrone reagent (0.2%). Anthrone was slowly added in concentration of H₂SO₄ through the wall of test tube and the content was mixed with a cyclomixer. The mixture was kept in boiling water for 10 min and cooled at room temperature. Absorbance of the solutions was measured at 620 nm against a suitable blank in which 1 ml distilled water was added to 4 mL anthrone in a UV-Spectrophotometer (Acm-34095-R).

The effect of populations and families on sixteen studied properties was analyzed using ANOVA. Populations and families were examined as fixed effects. Five replications of each property in randomized block design were analyzed for ANOVA. Furthermore, correlation coefficients between the pairs of fifteen properties were analyzed to see the relationship between them. Also relationship of altitude, longitude, and latitude to the sixteen studied properties was estimated through the analysis of correlation coefficient (Snedecer and Cochran, 1968). The ANOVA and correlation coefficient was done using MS Excel 2007. Tukey test (Bartz, 1988) was used to estimate the variation in morphological and chemical contents among the populations.

Results

The number of fruits kg-¹, fruit weight, diameter, length, volume, pulp thickness, and pulp:stone ratios are given in Table 2. Significant (p < .05) variation was observed in physical characters of aonla fruits among the populations. The lowest number of fruits kg-¹ (112.0) was recorded in Khola and highest in Paukhal seed source. The range of fruit weight (8.86–3.39 g), fruit diameter (2.34–1.78 cm), fruit volume (9.14–2.70 mL), pulp thickness (0.88–0.34), and pulp weight (8.70–2.19 g) were highest in Khola seed source and lowest in Paukhal seed source, respectively. However, the fruit length was highest (2.87 cm) in Khola and lowest (1.58 cm) at Kholachauri seed source. The pulp:stone ratio varied from 1.93 (Paukhal) to 9.82 (Chauki) among the populations. The specific gravity was maximum (1.31) in Dangchaura and minimum (1.01) in Chamoli seed source (Table 2).

Table 2. Physical variations in fruit characters of E. officinalis (mean of five replicate 20 fruits each). Value in the same column with the same letter do not differ significant (P < .05)

Population	Altitude (m asl)	Number of fruits kg^−1	Fruit weight (g)	Fruit diameter (cm)	Fruit length (cm)	Fruit volume (mL)	Pulp thickness (cm)	Pulp weight (g)	Pulp:stone ratio	Specific gravity
Kaudiyala	446	242 ^c	4.31°^p	1.89 ^k	1.64 ^m	3.50 ^mn	0.61^ef	3.77^mo	7.12^e	1.24^a
Devprayag	510	241 ^c	4.21^p	1.97^i	1.59 ^n	3.60 ^lm	0.48^jk	3.01^p	2.50 ^m	1.19^bcd
Satpuli	630	243 ^c	3.89^q	1.94 ^j	1.80^ij	3.20 ^n	0.49 ^j	3.15^p	2.76 ^lm	1.20^bc
Kaliyasauar	665	214^e	4.70 ^m	2.03^gh	1.72 ^l	4.60^hi	0.56 ^h	4.04^lmn	6.18 ^f	1.03^hi
Dangchaura	692	211^e	4.80^mn	2.01^hi	1.86 ^h	3.70^lmn	0.48^jk	3.55°	2.94^kl	1.31^a
Chauki	742	200 ^f	5.09^i	2.01^hi	1.84^hi	5.20 ^f	0.61^ef	4.62^hi	9.82^a	1.18^bcd
Khandah	742	199^fg	4.60 ^n	2.04 ^gh	1.75^kl	4.10^jk	0.53^i	3.52°	3.24^jk	1.13^def
Farashu	755	183 ^hi	5.52^ij	2.21^de	1.85 ^h	4.40^ij	0.63^e	4.36^ijk	3.83^h	1.26^a
Khankhara	758	145 ^l	7.02^d	2.35 ^c	1.95^ef	6.00^e	0.56 ^h	5.25^ef	2.94^kl	1.20^bc
Pathisain	759	162 ^k	6.24^fg	2.30^d	1.85 ^h	5.20 ^f	0.63^e	4.88^gh	3.57^hij	1.20^bc
Gauchar	790	170^jk	5.92 ^h	2.15 ^f	1.97^e	5.80^e	0.56 ^h	5.04^fg	6.01 ^f	1.02^i
Rudraparyag	798	120^mn	8.40^b	2.41^b	2.23^b	8.00 ^c	0.66^d	7.38 ^c	7.75^d	1.05^ghi
Karnaparyag	864	195^fg	5.21 ^kl	2.05^gh	1.84^hi	5.00^fg	0.57^gh	4.47^ij	6.06 ^f	1.06 ^ghi
Augastmuni	872	184 ^h	6.70^e	1.95 ^j	1.74 ^kl	3.40^mn	0.44 ^l	2.08^q	3.41^ij	1.13^def
Khola	919	112 ^n	8.86^a	2.87^a	2.34^a	9.14^a	0.88^a	8.70^a	6.15 ^f	1.14^ede
Pabau	1035	250 ^c	4.05^pq	1.93 ^j	1.65 ^m	3.80^klm	0.46^kl	2.89^p	2.50 ^m	1.09^egfh
Chamoli	1062	115 ^n	8.82^a	2.41^b	2.16 ^c	8.80^b	0.68 ^cd	7.87^b	8.31 ^c	1.01^i
Hisriyakhal	1119	128 ^m	7.90 ^c	2.42^b	2.25^b	6.60^d	0.74^b	6.30^d	3.96 ^h	1.20^bc
Naugad	1171	161 ^k	6.36 ^f	2.27^d	1.93^fg	5.30 ^f	0.59^fg	5.01^fg	3.79^hi	1.21^b
Bughani	1254	223^d	4.51^no	2.06^g	1.64 ^m	3.90^kl	0.53^i	3.53°	3.60^hij	1.18^bcd
Paukhal	1263	298^a	3.39 ^r	1.77 ^l	1.78^jk	2.70°	0.34 ^m	2.19^q	1.93 ^n	1.26^a
Jakheti	1320	188^gh	5.37^jk	2.11 ^f	1.98^de	4.50^hi	0.56 ^h	3.94^mn	2.76 ^lm	1.20^bc
Silkakhal	1426	184 ^h	5.47 ^j	2.09^fg	1.93^fg	5.10^fg	0.53^i	4.06^klmn	2.89^klm	1.07^fghi
Parsundakhal	1486	167^jk	6.04^g	2.20^de	2.02^d	4.80^gh	0.59^fg	4.67^hi	3.42^ij	1.26^a
Maikoti	1540	204^ef	4.92 ^lm	1.97^ij	1.84^hi	4.50^hi	0.53^i	4.11^klm	5.33 ^g	1.10^efg
Kholachauri	1552	283^b	3.59 ^r	1.82 ^k	1.58 ^n	3.30^mn	0.50 ^j	3.02^p	9.00^b	1.10^egf
Pauri	1563	173^ij	5.81^hi	2.21^de	1.73 ^l	5.68^e	0.60 ^f	4.29^lkj	2.82^klm	1.03^hi
Jakholi	1620	167^jk	6.10^fgh	2.25^de	1.91 ^g	5.90^e	0.57^gh	5.35^e	7.15^e	1.04^ghi
	SD	47.32	1.51	0.23	0.20	1.62	0.10	1.57	2.24	0.09

The moisture percentage, total soluble solids, malic acid, citric acid, tartaric acid, vitamin C, and sugar of the studied seed sources is presented in Table 3. There were significant (P< .05) variations in chemical parameters of aonla fruit among the populations. Moisture percentage values of aonla fruit ranged from 71.38% (Bughsni) to 83.42% (Kaliyasauar) among the populations.

Table 3. Chemical variations in fruit characters of E. officinalis (mean of five replicate 20 fruits each). Value in the same column with the same letter do not differ significant (P < .05)

Population	Altitude (m asl)	Moisture (%)	Total soluble solids (^°Brix)	Malic acid (%)	Citric acid (%)	Tartaric acid (%)	Vitamin C (mg100g^−1)	Sugar (mg g^−1)
Kaudiyala	446	83.30^a	14.16^jk	2.87^ijk	2.74^gh	6.42 ^f	347.92^gh	8.43^p
Devprayag	510	79.73^de	13.24^mn	2.80^ijk	2.68^gh	6.27^fg	294.26 ^k	13.62^mn
Satpuli	630	73.51 ^k	16.08	3.65^b	3.48^b	8.16^a	202.80 ^n	32.27 ^c
Kaliyasauar	665	83.42^a	15.84 ^f	2.88^hijk	2.75 ^g	6.45 ^f	471.90^b	14.01^mn
Dangchaura	692	73.60 ^k	17.24^d	3.23^d	3.09^d	7.23 ^c	374.05^e	26.03^d
Chauki	742	79.20^ef	16.20^ef	1.46	1.40 ^k	3.27 ^j	326.33^ij	23.34^e
Khandah	742	73.74^k	16.34^e	3.08^ef	2.95^e	6.90^d	252.84 ^l	14.60 ^lm
Farashu	755	79.13^ef	13.18^mn	2.90^ghij	2.77^fg	6.48^ef	370.44^ef	18.27 ^k
Khankhara	758	77.27 ^g	17.50 ^cd	3.51 ^c	3.36 ^c	7.86^b	355.42^fg	22.96^ef
Pathisain	759	73.10 ^k	19.70^b	3.71^b	3.55^ab	8.31^a	191.13 ^n	26.57^d
Gauchar	790	83.01^a	13.96^jkl	2.16 ^m	2.09^ij	4.89^hi	370.51^ef	19.69^ijk
Rudraparyag	798	83.23^a	17.28^d	2.76 ^k	2.64 ^h	6.18 ^g	488.49^a	30.09 ^c
Karnaparyag	864	80.33 ^cd	16.22^ef	2.12 ^m	2.02 ^j	4.74^i	454.60^bc	31.03 ^c
Augastmuni	872	81.40^b	13.08 ^n	2.92^ghi	2.79 ^f	6.54^ef	495.21^a	21.06^ghi
Khola	919	75.13 ^j	15.00^gh	3.78^a	3.61^a	8.46^a	296.77 ^k	45.30^a
Pabau	1035	75.54^ij	14.64^hi	3.20^de	3.07^d	7.20 ^c	222.96 ^m	21.37^fgh
Chamoli	1062	81.53^b	15.08^gh	2.13 ^m	2.04 ^j	4.77^i	247.53 ^l	34.45^b
Hisriyakhal	1119	82.00^b	10.68°	3.11^ef	2.97^de	6.96 ^c	312.75 ^j	11.27°
Naugad	1171	78.86 ^f	13.56 ^lm	2.87^ijk	2.74^gh	6.33^fg	402.68^d	34.94^b
Bughani	1254	71.38 ^l	21.42^a	3.67^b	3.51^ab	8.22^a	289.68 ^k	35.75^b
Paukhal	1263	76.52 ^h	13.36^mn	2.31 ^l	2.20^i	5.16 ^h	335.82^hi	16.45 ^l
Jakheti	1320	79.98 ^cd	14.34^ij	2.84^ijk	2.72^gh	6.36^fg	259.00 ^l	18.44 ^k
Silkakhal	1426	83.08^a	11.06°	3.65^b	3.48^b	8.16^a	410.75^d	21.93^fg
Parsundakhal	1486	78.55 ^f	15.10 ^g	3.02^fg	2.88^ef	6.75^de	201.41 ^n	12.83^no
Maikoti	1540	81.43^b	14.26^ijk	2.78^jk	2.63 ^h	6.15 ^g	191.62 ^n	20.21^hij
Kholachauri	1552	80.66 ^c	13.10 ^n	1.43 ^n	1.37 ^k	3.21 ^j	469.86^b	25.77^d
Pauri	1563	77.46 ^g	16.12^ef	3.65^b	3.48^b	8.19^a	404.07^d	19.03^jk
Jakholi	1620	81.99^b	13.82^kl	3.06 ^f	2.92^e	6.84^d	442.16 ^c	18.21^k
	SD	3.59	2.31	0.63	0.60	1.41	95.52	8.62

The total soluble solids were minimum (10.68%) in Hisriyakhal and maximum (21.42%) in Bughani seed source. The malic acid (3.78–1.43%), citric acid (3.61–1.37%), and tartaric acid (8.46–3.21%) contents were highest in Khola and lowest in Kholachauri seed source, respectively. Vitamin C content was lowest (191.13 mg 100 g⁻¹) in Pathisain and highest (495.21 mg 100 g⁻¹) in Augastmuni seed source. The sugar content was recorded highest (45.30 mg g⁻¹) in Khola and lowest (8.43 mg g⁻¹) in Kaudiyala seed source (Table 3).

Altitude had nonsignificant relationship with all physico-chemical characters of E. officinalis fruits. Latitude showed significantly (P< .05) negative correlation with malic acid, citric acid, and tartaric acid, while it demonstrated a positive significant (P< .1) relationship with moisture content. Vitamin C proclaimed positively significant (P< .05) correlation with latitude. Longitude had significant (P< .05) positive relationship with fruit weight. Malic acid, citric acid and tartaric acid were negatively correlated with longitude. Temperature did not show any relationship with physico-chemical characters of E. officinalis. Rainfall had significance (P< .05) negative correlation with number of fruit kg-¹ and specific gravity. Fruit weight, fruit diameter, fruit length, pulp thickness, pulp:stone ratio, and sugar contents had significant (P< .05) positive relationship with rainfall. Similarly, fruit volume had significant (P< .01) relationship with rainfall (Table 4a).

Significant positive (P< .01) relationship was recorded among the fruit dimension and associated characters. There was significant (P< .05) positive relationship between fruit weight versus malic acid, citric acid, tartaric acid and sugar content. Significant positive relationship was also recorded between fruit volume versus specific gravity and sugar content (P< .01), pulp weight versus specific gravity and sugar content (P< .01), pulp thickness versus specific gravity (P< .05), specific gravity versus moisture content (P< .05), moisture content versus vitamin C (P< .05), total soluble solid versus vitamin C, malic acid versus citric acid and tartaric acid (P< .01), and citric acid versus tartaric acid (P< .1) (Table 4b).

Significant inverse correlation was also found between fruit volume (P< .05) versus pulp:stone ratio, pulp:stone ratio (P< .05) versus specific gravity and moisture content, specific gravity (P< .05) versus malic acid, citric acid, and tartaric acid. There was significant (P< .05) negative correlation between moisture content versus total soluble solid, malic acid, citric acid, and tartaric acid (Table 4b).

The effect of populations for different physico-chemical characteristics exhibited highly significant (P< .05) variations (Table 5). However, the effect of families was not-significant in different characters except fruit volume and tartaric acid (i.e. P< .05).

Table 4a. Correlation coefficient between different physico-chemical characteristics and three geographical variables

Geographical attributes	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Altitude	−0.02^NS	0.01^NS	−0.01^NS	0.08^NS	0.06^NS	0.003^NS	−0.07^NS	−0.24^NS	−0.02^NS	0.11^NS	−0.24^NS	−0.02^NS	−0.03^NS	−0.02^NS	0.01^NS	0.01^NS
Latitude	−0.06^NS	0.14^NS	−0.03^NS	0.06^NS	0.14^NS	0.11^NS	0.04^NS	−0.17^NS	0.36^NS	0.55**	−0.35^NS	−0.39*	−0.38*	−0.39*	0.48*	−0.23^NS
Longitude	−0.36^NS	0.38*	0.14^NS	0.22^NS	0.34^NS	0.25^NS	0.06^NS	−0.56*	0.33^NS	0.32^NS	0.02^NS	−0.38*	−0.38*	−0.38*	0.21^NS	0.28^NS

*Significant at P < 0.05; **Significant at P < 0.01.

Abbreviation: 1. No of fruits/kg, 2. Fruit Weight, 3. Fruit Diameter, 4. Fruit Length, 5. Fruit Volume, 6. Pulp weight, 7. Pulp thickness, 8. pulp:stone ratio, 9. Specific gravity, 10. Moisture percent, 11. Total soluble solid, 12. Malic Acid, 13. Citric Acid, 14. Tartaric Acid, 15. Vitamin C, 16. Sugar content

Table 4b. Correlation coefficient between and among the various physico-chemical characteristics of Emblica officinalis.

-	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
2	−0.94**
3	−0.90**	0.89**
4	−0.83**	0.86**	0.84**
5	−0.88**	0.90**	0.90**	0.85**
6	−0.85**	0.87**	0.91**	0.87**	0.97**
7	−0.78**	0.76**	0.86**	0.72**	0.83**	0.89**
8	0.25	−0.26	−0.14	−0.09	−0.43*	−0.29	−0.14
9	−0.18	0.25	0.12	0.19	0.42*	0.45*	0.41*	−0.43*
10	−0.19	0.26	−0.02	0.19	0.23	0.19	0.13	−0.45*	0.49*
11	−0.06	−0.05	0.11	−0.13	0.05	0.07	0.03	0.06	0.00	−0.62*
12	−0.26	0.16	0.39*	0.12	0.08	0.08	0.17	0.18	−0.64*	−0.46*	0.27
13	−0.25	0.15	0.38*	0.11	0.08	0.07	0.17	0.18	−0.63*	−0.46*	0.27	0.99**
14	−0.26	0.15	0.39*	0.12	0.08	0.07	0.17	0.18	−0.64*	−0.47*	0.27	0.99**	0.99**
15	−0.03	0.10	−0.07	−0.06	0.04	−0.02	−0.07	−0.34	0.32	0.51*	−0.21	−0.27	−0.27	−0.27
16	−0.30	0.35	0.44*	0.34	0.45*	0.45*	0.33	−0.15	0.20	−0.38*	0.40*	0.12	0.11	0.12	0.01

*Significant at P < 0.05; **Significant at P < 0.01.

Abbreviation: 1. No of fruits/kg, 2. Fruit Weight, 3. Fruit Diameter, 4. Fruit Length, 5. Fruit Volume, 6. Pulp weight, 7. Pulp thickness, 8. pulp:stone ratio, 9. Specific gravity, 10. Moisture percent, 11. Total soluble solid, 12. Malic Acid, 13. Citric Acid, 14. Tartaric Acid, 15. Vitamin C, 16. Sugar content

Table 5. Analysis of variation for various physico-chemical characteristics among and within the population of E. officinalis.

Mean sum of squares of physico-chemical characters
Source of variation	DF	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Population	27	28.05**	42.77**	43.41**	21.54**	42.55**	61.96**	18.91**	21.99**	2.58**	34.96**	6.56.61**	82.37**	109.66**	104.99**	1305.44**	85.71**
Family	4	1.22	1.71	2.88*	1.97	2.34*	1.62	0.92	0.81	0.94	1.14	2.72*	0.62	2.32	3.25*	1.67	1.66

*Significant at P < 0.05; **Significant at P < 0.01.

Abbreviation: DF = Degrees of Freedom, 1. No of fruits/kg, 2. Fruit Weight, 3. Fruit Diameter, 4. Fruit Length, 5. Fruit Volume, 6. Pulp weight, 7. Pulp thickness, 8. pulp:stone ratio, 9. Specific gravity, 10. Moisture percent, 11. Total soluble solid, 12. Malic Acid, 13. Citric Acid, 14. Tartaric Acid, 15. Vitamin C, 16. Sugar content

Discussion

The nutritional status and quality of fruit is recognized by its composition, such as contents of sugars, acids, minerals, and other characteristics like aroma, texture, and flavor. All these parameters of fruits depend on plant genotypes, growing conditions, maturity, and time of harvesting (Hudina and Stampar, 2005). In the present study, significant physico-chemical variation was found in the fruits collected from different wild populations of Uttarakhand Himalaya. Fruits of natural growing trees have always the chance of unknown qualitative and quantitative characters due to a new set of genotypes. Also the quality parameters of fruits would be influenced by climactic factors like, temperature, rainfall, humidity, sunshine, phasing of sites/slopes, air current, nutritional status of soil, moisture condition of soil, and pH of soil of the area. Significant variation in morphological and chemical content of aonla fruit collected from different populations would be due to variation in climatic factors of their growing sites (Gutterman, 1992; Murali, 1997). Variation in different physico-chemical characters were also reported in Syzygium cumini (Devi et al., 2002), Pyrus germplasms (Ahmed et al., 2011), Rubus idoeus, Rubus discolor (Purgar et al., 2012), Arachis species (Chandran and Pandya, 2000), Cola nitida, (Adebola et al., 2002), Dioscorea cayenensis (Dansi et al., 1998), Choerospondies axillaries (Paudel et al., 2002), Irvingia gabonensis (Leakey et al., 2000), and in different cultivars of Citrus sinensis (Dubey, 2000).

The wide distribution of species with a set of different agro-climatic conditions may have different genetic constitutions in the fruits of aonla. Various physiological processes such as cell division, growth, and development, sugar metabolism, enzyme reactions, photosynthetic assimilation, and transportation are partially influenced by temperature variation. However, these differences are more evident in higher altitude and can be attributed to the differences in the solar radiation intensity.

The pheno-physiological (bud burst, berry growth, and development, berry size, numbers of berries per bunch, time of maturity and ripening) and biochemical (soluble sugar contents, titrable acidity, sugars, amino acids, organic acids, phenolic compounds, and total antioxidants) traits of table grapes varieties have been reported to vary with change in the site, locality, topography, and environment (Shiraishi et al., 2010).

Out of sixteen physico-chemical parameters in E. officinalis, seven parameters were significantly correlated with geographical variables (altitude, latitude, longitude). physico-chemical parameters did not exhibit any positive or negative trend with altitude. Latitude was inversely correlated with total soluble solid, malic acid, citric acid, and tartaric acid, indicating southern trend and positively significant with moisture and vitamin C content showing northern trend. The longitude exhibited positive correlation with fruit weight, indicating that this trait is increasing toward eastern extremes.

The inverse correlation of longitude with pulp:stone ratio, malic acid, citric acid, tartaric acid, indicates that these traits are increasing toward western extremes. Fruit weight of E. officinalis had positively significant correlation with fruit diameter, fruit length, fruit volume, pulp weight, and thickness. Similar results were also reported in mango cultivars (Attri et al., 1999).

The results of this study bring out the fact that the fruits of E. officinalis collected from different populations have large variation in physico-chemical characters. However, the variations were random between collection sites. Therefore, all these study parameters should be considered as improvement properties for the selection in E. officinalis. Furthermore, the characters which showed greater influence i.e. fruit weight, fruit volume, pulp weight, specific gravity, tartaric acid, vitamin C, sugar content can be directly screened/selected for the improvement of this potential fruit species. Wild fruit of E. officinalis is the great source of nutrients for the human health in any region of the world and the wild races in several regions in India is overexploited due to high market demand. But in Himalayan region, the wild population of aonla is not exploited rather negated due to unavailability of market (local “mandee” sale of the fruit).

Consequently, the local inhabitants of Himalayan region cut the wild aonla tree for fuel and fodder purposes and some extent the aonla fruit is used for making pickle and juices. Therefore, the natural population of aonla is declining day by day. Further investigation is needed to select the best sources for production of best quality seedlings for afforestation and reforestation programs, particularly in hill Region of India and also the focus should be given on the in-situ conservation of wild races of E. officinalis. The conservation of wild aonla germplasm is good for ecological and economic points of view. The sustainable harvesting of aonla is required from its wild population for the upscaling of socio-economic status of the rural natives of aonla growing regions in India.

Acknowledgments

First and second authors are thankful to Herbal Research and Development Institute, Gopeshwar, Chamoli, Uttarakhand, India for financial assistance and Authors are thankful to Head, Department of Horticulture, H.N.B. Garhwal University (A Central University) and Dean, College of Forestry, Ranichauri, V.C.S.G., Uttarakhand University of Horticulture and Forestry, Bharsar for the providing Laboratory facilities. The authors are thankful to the anonymous reviewers of the earlier draft of this manuscript for their valuable comments and suggestions.