Physicochemical and Processing Qualities of Guava Varieties in Kenya

Figures & data

Table 1. Physical characteristics of the common Kenyan guavas varieties.

Fruit parameters	Fruit varieties
	Red/Pink fleshed	White fleshed	Strawberry
Fruit shapes	Ovoid Pear-shaped Round	Ovoid Pear-shaped Round	Round
Ripe fruit peel color	Yellow Green – Yellow	Yellow Green-Yellow	Red-Purple
Ripe Flesh color	Red/pink	White	Creamy- white
Fruit Weights (g)	148.92 ± 109.52^b	126.64 ± 85.08^b	5.68 ± 1.96^a
Fruit Diameter (cm)	5.00 ± 0.90^b	4.83 ± 1.07^b	2.10 ± 0.26^a
Fruit Length (cm)	5.20 ± 0.70^b	4.87 ± 1.08^b	2.13 ± 0.35^b
Seed weight (per 100 g)	2.4 ± 0.8^a	3.9 ± 1.0^ab	4.9 ± 0.6 ^c
Pulp Weight (per 100 g)	71.3 ± 0.9 ^c	65.7 ± 2.1^b	58.6 ± 2.5^a
Pulp: Seed ratio (g/g)	31.2 ± 8.8^b	17.8 ± 4.6^ab	12.1 ± 2.5^a

Values (means± standard deviation) with different superscripts across the row are statistically different (Tukey’s test, P < 0.05).

Figure 1. A- Cross-sectional view of the ripe pear-shaped, round, and ovoid red-fleshed guavas. B- Ovoid, round and pear-shaped whole white-fleshed guavas.

Table 2. Guava fruit flesh color for the red, white, and strawberry guava varieties.

Guava Varieties	Color parameters
	L	a*	b*	Chroma*	Hue angle*
Red guava	50.52 ± 2.43^a	22.63 ± 3.93 ^c	17.12 ± 2.66^b	28.45 ± 4.06^b	37.51 ± 3.92^b
White	77.87 ± 8.19^b	2.46 ± 1.44^a	31.21 ± 7.62 ^c	31.69 ± 7.27^b	86.02 ± 1.83 ^c
Strawberry	44.97 ± 2.81^a	9.97 ± 2.29^b	4.75 ± 1.19^a	11.29 ± 1.82^a	24.45 ± 5.66^a
Overall Mean (Range)	59.39 (40.64–91.40)	11.90 (0.84–31.53)	19.31 (3.32–41.83)	25.38 (8.04–42.16)	52.44 (18.80–88.18)
Coefficient of variation (%	26.3	78.58	60.1	38.54	51.84
P value	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001

Color values are expressed as mean ± standard deviation. Values with different superscripts along a column are statistically different (Tukey’s test, P<0.05).

Figure 2. Color images of whole and cross-sectional fruits' skin and flesh. A - red-fleshed, B - white-fleshed, and C -for strawberry guavas. Proximate composition of guava fruits.

Table 3. ANOVA table for the variations in the fruit’s chemical composition.

Source of variation	ANOVA parameters
	R^2	F	Pr > F
Moisture	0.653	27.246	<0.0001
Ash	0.071	1.100	0.346
Crude Protein	0.141	2.385	0.110
Crude Fat	0.016	0.235	0.792
Crude Fiber	0.191	3.424	0.046
Carbohydrates	0.201	3.640	0.039
Energy	0.184	3.266	0.053
Tss	0.697	33.355	<0.0001
Ph	0.907	141.989	<0.0001
Titratable acidity	0.867	94.229	<0.0001
TSS/TTA Ratio	0.560	18.434	<0.0001
Vitamin C	0.930	192.145	<0.0001
Zinc	0.275	5.512	0.009
Iron	0.387	9.145	0.001
Calcium	0.302	6.269	0.005
Potassium	0.644	26.193	<0.0001
Flavonoids	0.256	4.996	0.014
Phenolics	0.197	3.553	0.042
Antioxidant activity	0.189	3.382	0.048

Table 4. Proximate composition of the red, white, and strawberry guava varieties.

Fruit varieties	Moisture (%)	Dry matter (%)	Parameters (per 100 g dry weight basis)
			Ash (g)	Crude Protein (g)	Crude Fat (g)	Crude Fiber(g)	Carbohydrates (g)	Energy (Kcal)
Red	84.08 ± 2.32^b	15.92 ± 2.32^a	0.53 ± 0.12^a	0.36 ± 0.40^a	0.47 ± 0.08^a	32.78 ± 0.72^a	65.86 ± 0.97^b	269.12 ± 2.59^a
White	82.77 ± 1.05^b	17.23 ± 1.05^a	0.52 ± 0.11^a	0.50 ± 0.43^a	0.46 ± 0.07^a	33.63 ± 1.79^ab	64.89 ± 2.04^ab	265.71 ± 7.35^a
Strawberry	78.58 ± 1.13^a	21.42 ± 1.13^b	0.70 ± 0.54^a	0.78 ± 0.44^a	0.48 ± 0.03^a	35.69 ± 4.38^b	62.35 ± 5.14^a	256.86 ± 19.30^a
Mean (Range)	82.21 (76.60–88.97)	17.79 (11.03–23.40)	0.57 (0.35–1.94)	0.52 (0.09–1.22)	0.47 (0.22–0.54)	33.83 (32.30–42.77)	64.62 (53.53–66.50)	264.78 (223.86–270.86)
Coefficient of variation (%)	3.32	15.36	50.31	85.06	13.56	7.82	4.83	4.3
P value	<0.0001	<0.0001	0.346	0.110	0.792	0.046	0.039	0.053

Values (means± standard deviation) with different superscripts along a column are statistically different (Tukey’s test).

Table 5. Class centroid for the AHC fruit composition classification.

Fruit parameter	Class centroid
	1	2
Dry matter	16.577	21.419
Moisture	83.423	78.581
Ash	0.523	0.695
Crude Protein	0.431	0.779
Fat	0.465	0.481
Crude Fiber	33.205	35.691
Carbohydrates	65.376	62.354
Energy	267.413	256.861
Tss	10.679	12.950
Ph	3.875	2.913
Titratable acidity	0.677	1.426
TSS/TTA Ratio	16.376	9.128
Vitamin C	1515.354	164.113
β-carotenes	1.008	1.548
Zinc	4.463	6.832
Iron	12.852	32.571
Calcium	11.383	18.840
Potassium	233.096	413.560
Flavonoids	194.332	250.658
Phenolics	1517.844	1410.274
Antioxidant activity	844.148	736.404

Figure 3. Dendrogram dissimilarity plot classification for the strawberry (St), White (Wt), and Red (Rd) guava varieties.

Figure 4. The PCA biplot for guava nutrient compositions. St- strawberry, Wt- White and Rd- Red guava.

Table 6. Chemical, mineral, and phytochemical characterization of red, white and strawberry guava fruits.

Parameter	Guava varieties			Mean (Range)	Coefficient of variation (%)	P value
	Red guava	White	Strawberry
Total soluble solids (^oBrix f.w.)	10.65 ± 0.62^a	10.71 ± 0.91^a	12.95 ± 0.17^b	11.25 (9.30–13.20)	10.64	<0.0001
Ph (f.w)	3.82 ± 0.11^b	3.93 ± 0.10^b	2.91 ± 0.22^a	3.63(2.72–4.10)	12.31	<0.0001
Titratable acidity (%)	0.65 ± 0.13^a	0.70 ± 0.15^a	1.43 ± 0.12^b	0.86 (0.53–1.58)	41.07	<0.0001
Vitamin C (mg/100 g d.w)	1365.15 ± 250.56^b	1665.56 ± 126.50 ^c	164.11 ± 11.85^a	1177.54 (149.75–1948.56)	53.63	<0.0001
Beta carotenes (mg/100 g d.w)	1.98 ± 0.62^b	0.04 ± 0.06^a	1.55 ± 0.30^b	1.14 (0.00–2.88)	84.95	<0.0001
Zinc (mg/100 g d.w)	5.35 ± 1.69^ab	3.76 ± 2.91^a	6.83 ± 1.41^b	5.06 (1.40–9.75)	49.11	0.009
Iron (mg/100 g d.w)	17.30 ± 16.28^b	8.41 ± 3.26^a	32.57 ± 14.24^b	17.78 (3.34–46.53)	3.34	0.001
Potassium (mg/100 g d.w)	234.96 ± 37.32^a	231.23 ± 85.80^a	413.56 ± 41.27^b	278.21 (168.36–467.74)	35.58	<0.0001
Calcium (mg/100 g d.w)	13.96 ± 8.69^ab	8.80 ± 2.58^a	18.84 ± 5.81^b	13.25 (2.29–28.01)	54.81	0.005
Total flavonoids (mg CE/100 g d.w)	200.41 ± 39.52^a	188.25 ± 30.33^a	250.66 ± 66.04^b	208.41 (128.69–333.33)	24.03	0.014
Total phenolic (mg GAE/100 g d.w)	1649.14 ± 329.70^b	1386.54 ± 243.07^a	1410.27 ± 134.24^ab	1490.95 (1036.23–2460.94)	18.87	0.042
Antioxidant activity (µMTE/100 g d.w)	989.14 ± 383.47^b	699.15 ± 207.46^a	736.40 ± 230.28^ab	817.21 (376.07–1970.76)	38.30	0.048

Values (means± standard deviation) with different superscripts across the rows are statistically different (Tukey’s test, P < 0.05).