Effects of plant density and fertilizer formula on physicochemical and sensorial characteristics of pasteurized juice from Perolera sugarloaf pineapples grown in the long rainy season

Figures & data

Fig. 1 Flow chart for the production of pasteurized pineapple juice.

Table 1 Attributes, definitions, and reference standards generated by the sensory judges.

Attribute	Definition	Highest scale reference
Appearance
Viscosity	Flow rate of the juice when it runs down along the cup wall.	Extremely viscous: Baobab juice (density = 1.11)
Yellow color	Yellow color characteristic of pineapple fruit juice perceived as a sensation produced by stimulation of the retina.	Extremely yellow: Smooth cayenne mature pineapple juice with yellow color reference ^(†).
Brown color	Brownish color characteristic of pineapple fruit juice which has been subjected to high thermal processing for long cooking times.	Extremely brown: overcooked pineapple juice with brownish yellow color reference ^(†).
Taste
Acid	Taste stimulated by the presence of acid substances in the mouth.	Extremely acid : lemon juice diluted in water at concentration of 20% (v/v) with a pH of 2.86
Sweet	Taste stimulated by the presence of sucrose and other substance such as sweetener.	Extremely sweet : sugar solution (140 g/l) with 16.6 degree Brix
Overcooked	Bitter sensation perceived at the back of the throat after having swallowed pineapple fruit juice that was subjected to high thermal processing for long cooking times.	Much pronounced : overcooked pineapple juice
Pineapple aroma	Characteristic aroma of natural mature pineapple fruit.	Much pronounced : small pieces of pineapple fruits

^†Yellow sensory reference color = L: 78.76 ± 0.6; a: -5.24 ± 0.1; b: 27.68 ± 1.3; ΔE: 11.01 ± 0.8.

^†Brownish yellow color reference = L: 56.93 ± 0.3; a: 8.01 ± 0.1; b: 26.6 ± 0.1 ; ΔE: 26.42 ± 0.4.

Fig. 2 Linear structured intensity scale used for sensory tests.

Table 2 Physicochemical characteristics of the nine pasteurized pineapple juices.

	Treatments	pH	degree Brix	density
Juices	D1E1	4.11 ± 0.03^a	13.1 ± 0.27^a	1.04 ± 0.01^a
	D1E2	4.17 ± 0.01^ab	14.4 ± 0.12^b	1.05 ± 0.01^a
	D1E3	4.18 ± 0.07^ab	13.8 ± 0.34^abc	1.04 ± 0.0^a
	D2E1	4.12 ± 0.00^ab	13.5 ± 0.31^ac	1.04 ± 0.01^a
	D2E2	4.14 ± 0.04^ab	14.1 ± 0.35^bc	1.04 ± 0.0^a
	D2E3	4.16 ± 0.05^ab	14.1 ± 0.2^bc	1.04 ± 0.01^a
	D3E1	4.22 ± 0.03^b	13.7 ± 0.32^abc	1.04 ± 0.01^a
	D3E2	4.18 ± 0.02^ab	13.2 ± 0.46^ac	1.04 ± 0.0^a
	D3E3	4.13 ± 0.03^ab	13.8 ± 0.21^abc	1.04 ± 0.0^a
ANOVA P-values	planting density	0.169	0.129	0.832
	K2O:N ratio	0.783	0.006**	0.626
	treatment	0.03*	0.001**	0.804

Means with the same letter in a column do not significantly differ at 5 % level by Tukey's means test.

*, **, ***Significant at P < 0.05, P < 0.01 and P < 0.001, respectively.

Table 3 L*, a*, b* and ΔE values for the nine pasteurized pineapple juices.

	Treatment	Lightness L*	Redness a*	Yellowness b*	ΔE‡
Juices	D1E1	79.08 ± 1.2^a	0.6 ± 0.4^a	7.76 ± 2.7^a	28.19 ± 2.5 ^a
	D1E2	77.43 ± 1.0^ab	−0.11 ± 0.3^ab	12.34 ± 1.4^b	23.85 ± 1.2 ^a
	D1E3	76.94 ± 1.8^ab	−0.49 ± 0.6^abc	16.71 ± 1.6^c	19.73 ± 1.3 ^b
	D2E1	75.13 ± 1.3^b	−2.18 ± 0.2^d	21.25 ± 0.9^de	16.22 ± 0.4 ^c
	D2E2	74.46 ± 2.5^b	−0.93 ± 0.9^bcd	21.04 ± 1.2^de	16.75 ± 0.4 ^cd
	D2E3	74.87 ± 1.7^b	−1.4 ± 0.4^cd	21.47 ± 1.9^de	16.01 ± 1 ^c
	D3E1	78.24 ± 0.2^ab	−1.96 ± 0.2^d	17.47 ± 0.6^ce	18.92 ± 0.6 ^bd
	D3E2	79.16 ± 0.4^a	−2.17 ± 0.1^d	16.37 ± 0.9^bc	19.94 ± 0.8 ^b
	D3E3	74.36 ± 0.5^b	−1.51 ± 0.3^cd	22.24 ± 1.2^d	15.5 ± 0.8 ^c
ANOVA P-values	Planting density	0.000***	0.000***	0.000***	0.000***
	K2O:N ratio	0.012*	0.864	0.000***	0.000***
	Treatments	0.001**	0.000***	0.000***	0.000***

Means with the same letter in a column do not significantly differ at 5 % level by Tukey's means test.

*, **, *** Significant at P < 0.05, P < 0.01 and P < 0.001, respectively.

‡ Standard yellow calibration curve plate (L = 80.89; a* = 1.95; b* = 35.83).

Fig. 3 Distribution of the sensory descriptors according to the mean of their intensities.

Table 4 Significant influence of the treatments on the juice’s sensorial parameters.

	ANOVA P-values and significant levels
Descriptors	Planting density	K2O:N ratio	Treatments
Sweet taste	0.114	0.35	0.015*
Acid taste	0.044*	0.000***	0.000***
Pineapple aroma	0.412	0.115	0.037*
Yellow color	0.41	0.87	0.003**
Brown color	0.644	0.000***	0.000***
Viscosity	0.971	0.001**	0.003**

*, **, ***Significant at P < 0.05, P < 0.01 and P < 0.001, respectively.

Fig. 4 Biplot of CCSWA performed on the 02 datasets.

Fig. 5 Boxplots of the physicochemical parameters of the nine juices.

Fig. 6 Boxplots of the sensory data of the nine juices.

Fig. 7 Average acceptance scores for the pasteurized juices (14 panelists, 3 replications).