Study of Physicochemical Properties of Dried Kiwifruits Using the Natural Hypertonic Solution in Ultrasound-assisted Osmotic Dehydration as Pretreatment

Figures & data

Table 1. The physicochemical properties of the grape and mulberry syrups

Parameters	Grape syrup	Mulberry syrup
Soluble dry matter (%)	71.91 ± 2.31^a	72.23 ± 2.85 ^a
Total sugar (g/100 g)	60.57 ± 3.76 ^a	58.51 ± 3.93 ^a
Fructose (g/100 g)	29.65 ± 1.84 ^a	29.05 ± 2.06 ^a
Glucose (g/100 g)	30.08 ± 1.75 ^a	28.91 ± 1.77 ^a
Sucrose (g/100 g)	0.84 ± 0.17 ^a	0.55 ± 0.10 ^a
Ash (%)	2.01 ± 0.13 ^a	2.24 ± 0.15 ^a
pH	5.11 ± 0.19 ^a	5.03 ± 0.23 ^a
Protein (%)	1.81 ± 0.48 ^a	1.94 ± 0.66 ^a
Titratable acidity (% citric acid)	0.57 ± 0.08 ^a	0.61 ± 0.10 ^a
L*	23.64 ± 3.17 ^a	27.09 ± 2.36 ^a
a*	8.22 ± 1.69 ^a	7.04 ± 2.01 ^a
b*	1.07 ± 0.82 ^a	3.26 ± 1.02^b

Means followed by the same letters in rows are not significantly different (p < .05).

Table 2. The effect of type of osmotic solution and ultrasonic time on the moisture content (%), water loss (%), solid gain (%), shrinkage (%), vitamin C (mg/100 g), and total chlorophyll (mg/kg) of the kiwifruit slices during the osmotic-ultrasound-assisted osmotic dehydration pretreatment

		Moisture (%)				Water loss (%)
Ultrasound time(min)	Mulberry syrup	Grape syrup	Sugar	Distilled water	Mulberry syrup	Grape syrup	Sugar	Distilled water
20	45.87 ± 1.80^Caa	42.25 ± 1.38^Ca	54.38 ± 2.95^Cb	67.19 ± 1.33^Cc	14.50 ± 2.31^Ab	17.13 ± 1.48^Ab	8.08 ± 0.72^Aa	7.74 ± 1.71^Aa
30	32.34 ± 2.23 ^Ba	28.22 ± 2.52 ^Ba	43.43 ± 2.27^Bb	61.88 ± 1.87^Bc	18.54 ± 2.25^Ab	20.21 ± 2.65^Ab	9.06 ± 2.19^Aa	7.92 ± 1.13^Aa
40	22.41 ± 2.24^Aa	20.76 ± 1.81^Aa	39.90 ± 1.44^Ab	49.58 ± 2.45^Ac	36.83 ± 4.75^Bb	37.20 ± 3.42^Bb	11.58 ± 1.43 ^Ba	9.03 ± 1.91 ^Ba
		Solid gain (%)				Shrinkage (%)
20	6.41 ± 1.44^Ac	7.33 ± 1.58^Ac	2.13 ±.94^Ab	1.40 ±.29^Aa_	36.83 ± 3.09^Ab	31.88 ± 1.78^Aa	46.83 ± 2.55^Ab	50.93 ± 2.40^Ac
30	6.52 ± 1.54^Ab	7.58 ± 1.66^Ab	3.40 ±.91 ^Ba	2.78 ± 1.23^Ba_	51.63 ± 1.61^Bb	46.33 ± 1.56 ^Ba	63.93 ± 2.57^Bb	68.93 ± 1.85^Bc
40	9.70 ± 1.68^Bb	9.87 ± 1.64^Bb	3.64 ±.84 ^Ba	2.85 ± 1.25^Ba_	58.67 ± 2.45^Cb	48.52 ± 2.46 ^Ba	78.27 ± 2.07^Cc	81.66 ± 1.56^Cc
		Vitamin C(mg/100 g)				Total chlorophyll (mg/kg)
20	56.90 ± 1.88^Cc	69.20 ± 1.95^Bd	45.17 ± 1.47^Cb	31.16 ± 2.15^Ca	0.36 ± 0.10 ^Ba	0.56 ± 0.08^Ab	0.32 ± 0.07^Ca	0.34 ± 0.15^Ca
30	48.60 ± 1.68^Bc	58.20 ± 1.98^Ad	36.96 ± 1.94^Bb	28.94 ± 1.38 ^Ba	0.23 ± 0.09^Bb	0.48 ± 0.10^Ac	0.21 ± 0.16^Bb	0.17 ± 0.01 ^Ba
40	38.13 ± 1.74^Ac	56.90 ± 2.14^Ad	30.50 ± 1.73^Ab	19.67 ± 1.67^Aa	0.17 ± 0.01^Ab	0.29 ± 0.12^Ac	0.14 ± 0.02^Aa	0.11 ± 0.10^Aa

^aMeans followed by the same letters, lower case in rows and capital in columns, are not significantly different (p < .05).

Figure 1. The effect of type of osmotic solution and ultrasonic time on the firmness of the dried kiwifruit slices

Table 3. The effect of type of osmotic solution and ultrasonic time on the color characteristics of the dried kiwifruit slices

	L* value				a* value				b* value
Ultrasound time(min)	Mulberry syrup	Grapesyrup	Sugar	Distilledwater	Mulberrysyrup	Grapesyrup	Sugar	Distilledwater	Mulberry syrup	Grapesyrup	Sugar	Distilled water
20	40.36 ± 0.92^Ab	41.52 ± 0.53^Ab	49.33 ± 0.98^Bc	42.29 ± 0.67^Aa	−1.92 ± 0.26^Ab	1.50 ± 0.24^Ac	−4.62 ± 0.28 ^Ba	−4.85 ± 0.41 ^Ba	16.28 ± 0.66^Bc	9.56 ± 0.78^Aa	13.77 ± 0.65^Cb	16.52 ± 0.20^Bc
30	39.17 ± 0.91^Bb	38.99 ± 0.71^Bb	42.41 ± 0.91^Bc	35.78 ± 0.95^Aa	−1.63 ± 0.06^Ac	2.18 ± 0.04^Ad	−4.03 ± 0.04 ^Ba	−2.98 ± 0.14^Ab	14.98 ± 0.98^Bb	9.33 ± 0.70^Aa	10.65 ± 0.84 ^Ba	9.96 ± 0.53^Aa
40	25.28 ± 0.67^Aa	24.35 ± 0.79^Aa	21.56 ± 0.79^Aa	28.86 ± 0.93^Bb	−1.13 ± 0.01^Ab	2.54 ± 0.06^Bc	−2.60 ± 0.12^Aa	−2.76 ± 0.31^Aa	11.83 ± 0.83^Ab	9.11 ± 0.12^Aa	7.50 ± 0.08^Aa	8.33 ± 0.42^Aa

Figure 2. The effect of type of osmotic solution and ultrasonic time on the sensory properties of the dried kiwifruit slices