Progress on research and development of goji berry drying: a review

Figures & data

Table 1. HAD, hot air drying; HPD, heat pump drying; FIRD, far Infrared Drying kinetic parameters with different drying methods

Variety	Drying Method	Pretreatment		Operating conditions	Drying time (h)	Effective diffusivity (m^2/s)	Activation energy (kJ/mol)	Reference
Ning Qi 1	HAD	-		50°C, RH20%,2 m/s	24	1.04 × 10^−8	48.37	93
				60°C, RH20%,2 m/s	19	1.31 × 10^−8
				70°C, RH20%,2 m/s	9	2.98 × 10^−8
Ning Qi 7	HAD	soaked in sodium carbonate solution (30 g/kg), 1 min		40°C	27	5.00 × 10^−11	49.65	94
				50°C	50	8.94 × 10^−11
				60°C	86	16.10 × 10^−11
		-		40°C	36	4.13 × 10^−11	50.71
				50°C	70	6.70 × 10^−11
				60°C	110	12.90 × 10^−11
Ning Qi	HAD			50, RH30%, 0.2 m/s	44	7.6 × 10^−11	61.36	95
				55, RH30%, 0.2 m/s	36	9.4 × 10^−11
				60, RH30%, 0.2 m/s	24	16.1 × 10^−11
				65, RH30%, 0.2 m/s	20	19.8 × 10^−11
Ning Qi 7	HPD	soaked in sodium carbonate solution (30 g/kg), 1 min		52°C-64°C;60%-10%	32	-	-	62
Ning Qi 5	FIRD	soaked in sodium carbonate solution (0.4%)	30% sucrose solution permeated	70°C, irradiation height 210 mm	13	0.87 × 10^−7	-	96
			40 KHz, 60°C by ultrasound		10	1.05 × 10^−7
			40 KHz, 60°C by ultrasound+Hot scalding with distilled water at 100°C		9.5	1.29 × 10^−7
			40 KHz, 60°C by ultrasound+30% sucrose solution permeated		10.2	1.23 × 10^−7
			40 KHz, 60°C by ultrasound+Hot scalding with distilled water at 100°C		8.7	1.33 × 10^−7
			-		18	0.94 × 10^−7
Ning Qi 1	MD	soaked in sodium carbonate solution		Pulse ratio 1.67, microwave power 185 W	9	5.28 × 10^−11	54.78	97
				Pulse ratio 1.67, microwave power 200 W	8	9.17 × 10^−11
				Pulse ratio 1.67, microwave power 215 W	6	1.42 × 10^−10
				Pulse ratio 1.50, microwave power 200 W	6	8.89 × 10^−11
				Pulse ratio 1.67, microwave power 200 W	8	9.17 × 10^−11
				Pulse ratio 2.00, microwave power 200 W	20	2.03 × 10^−10

Table 2. Variation of quality of Lycium barbarum with different drying methods

Variety	Drying Method	Pretreatment		Dry	Color Change				Reference
				Conditions	L *	a *	b *	ΔE
Ning Qi 1	HAD	fresh		-	25.97 ± 0.12a	25.16 ± 0.13a	17.30 ± 0.15a	-	93
		-		50°C, RH20%,2 m/s	23.11 ± 0.09b	16.45 ± 0.07b	11.03 ± 0.11b	10.87
				60°C, RH20%,2 m/s	22.79 ± 0.05c	14.41 ± 0.09c	10.67 ± 0.07c	13.01
				70°C, RH20%,2 m/s	21.99 ± 0.06d	14.67 ± 0.08d	9.62 ± 0.05d	13.91
Ning Qi 7	HAD	fresh		-	47.18 ± 0.12a	41.78 ± 1.21a	18.96 ± 0.76a	0a	94
		-		40°C	40.65 ± 0.21b	28.14 ± 0.42d	12.49 ± 1.02c	16.45 ± 0.54c
				50°C	38.88 ± 0.88c	24.46 ± 0.40c	10.42 ± 0.55de	21.02 ± 0.19d
				60°C	36.90 ± 0.53d	18.29 ± 1.72e	8.29 ± 1.02 g	27.78 ± 2.11e
		soaked in sodium carbonate solution (30 g/kg)		40°C	40.98 ± 1.17b	31.51 ± 0.08b	14.90 ± 0.01b	12.67 ± 0.33b
				50°C	40.86 ± 0.36b	28.27 ± 0.12c	11.99 ± 0.50 cd	16.48 ± 0.34c
				60°C	37.30 ± 0.21d	20.17 ± 2.46e	9.22 ± 1.29ef	25.69 ± 2.42e
Ning Qi 5	fresh			-	39.480	41.941	26.31	-	96
	FIRD	soaked in sodium carbonate solution (0.4%)	30% sucrose solution permeated	70°C, irradiation height 210 mm	38.566	37.678	20.396	7.3467
			40 KHz, 60°C by ultrasound		37.95	36.512	19.402	8.9918
			40 KHz, 60°C by ultrasound+Hot scalding with distilled water at 100°C		37.574	39.348	19.132	7.8661
			40 KHz, 60°C by ultrasound+30% sucrose solution permeated		39.700	38.354	20.588	6.7564
			40 KHz, 60°C by ultrasound+Hot scalding with distilled water at 100°C		37.236	39.052	17.901	9.1708
			-		35.978	39.923	18.136	9.1185
	Natural drying	-		-	40.216	44.970	21.358	5.8519
Ning Qi 5	Natural drying	soaked in sodium carbonate solution (5%)		-	24.46 ± 1.36	20.19 ± 3.32	31.29 ± 2.31	19.72 ± 2.61	100
	Coal burning drying house				30.08 ± 0.45	28.16 ± 1.43	27.35 ± 3.21	17.43 ± 1.97
	Solar energy equipment				35.97 ± 1.82	33.40 ± 3.26	24.06 ± 2.24	17.11 ± 1.46
	fresh				47.55 ± 0.20	44.41 ± 1.17	41.82 ± 1.05	55.13 ± 2.23

Different letters in the same cultivar indicate significant differences (P < 0.05).