| With the characteristics of high water content and delicate tissue, the strawberry is highly susceptible to mechanical damage and decay caused by microbials, which seriously affect the postharvest circulation of strawberry. So, on the basis of investigating the effects of storage temperature on the quality of strawberry, the report investigated the effect of different methods, such as precooling, storage, transportation, sales and home preservation, on the quality of strawberry, aiming to provide theoretical basis and technical reference for strawberry fresh-keeping and cold chain logistics. The results of this study are as follows:1. Effects of different storage temperature(0, 5, 10, 15, 20, 25 and 30℃) on respiration rate and quality of strawberry were studied. The results showed that the higher the temperature was, the higher the respiration rate, the shorter the shelf life.The shelf life of strawberry were 9d, 7d, 5d, 4d, 3d, 2d and 8h at 0, 5, 10, 15, 20, 25 and 30℃, respectively. The quality of strawberry stored at 0℃ was the best. After 9d storage, its sensory evaluation, weight loss, firmness, relative conductivity, sugar-acid ratio, Vitamin C content, L*, hue and C* value were 5.4, 3.18%, 11.13 N, 39.05%, 12.48, 22.01mg/100 g, 37.84, 32.81, 45.59, respectively.2.Effects of different precooling methods on quality of strawberry were studied. The strawberry was packaged plastic clamshell containers within carton, the precooling time, weight loss, respirationrate and ethylene production of strawberry cooled by forced-air precooling and room precooling were studied. The results show that the precooling time of strawberry cooled by forced-air cooling and room cooling from 21℃ down to 3℃ were 120 min, 360 min, respectively. The weight loss of strawberry cooled by force-air cooling and room cooling were 0.13%, 0.22%, respectively. The precooling can reduce the respiration rate and ethylene production of strawberry effectively. The quality of strawberry cooled by forced-air cooling was the best.3. Effects of different storage methods on quality of strawberry were studied. 0℃cold storage as control, the effect of 1-MCP, controlled atmosphere(CA), 1-MCP+CA on quality of strawberry were studied. The result show that 1-MCP, CA and 1-MCP+CA can inhibit the respiration rate and ethylene production effectively, keep the good quality and prolong the shelf life of strawberry. The treatment of 1-MCP+CA keep the best quality of strawberry among four treatments; the shelf life of strawberry can be extended to 18 d. After 18 d cold storage, the sensory evaluation of strawberry in 1-MCP+CA was 5.9; the weight loss, firmness, relative electric conductivity, sugar-acid ratio, Vc content were 0.77%, 9.9N, 44.74%, 14.28, 83.83mg/100 g, respectively; the L*, hue and C* value were 34.29, 31.70, 47.36, respectively; the content of total phenols, anthocyanin, flavonoid were 470.59 mg/100 g, 5.71 U.g-1, 0.60 OD325 mm.g-1, respectively; the PPO activity and CAT activity were 0.27 U.g-1FW.min-1, 32.56 U.g-1FW.min-1, respectively.4.Effects of different transportation methods on quality of strawberry were studied. Strawberries were transported when the core temperatures of strawberries dropped to about 0℃ by forced-air cooling. Plastic clamshell containers with carton packaging and cooler box under normal temperature, plastic clamshell containers with carton box packaging under 0℃were used to simulate three transportations. The result showed that the core temperature of strawberry in plastic clamshell containers with carton packaging under normal temperature increased from 0℃ to near ambient temperature 20.6℃ after 12 h transportation, the sensory evaluation and weight loss of strawberry was 7.0 after 1d transportation, the quality cannot be guaranteed during retailing. The core temperature of strawberry in cooler box can keep 3℃ for 8h, the sensory evaluation of strawberry decreased to 8.2 after 1d transportation. The strawberry in plastic clamshell containers with carton box packaging under 0℃ transportation kept the best quality, the sensory evaluation and weight loss of strawberry was 8.3 and 1.65% after 2d transportation, This transportation method can reduce the increase of relative electric conductivity and the decrease of sugar-acid ratio, Vc content.5.Effects of different retailing methods on quality of strawberry were studied. Strawberries, which were transported at 0℃ for 1d, were retailed respectively at 4℃with humidification(relative humidity 90-95%), 4℃ in closed refrigerated display and room temperature(23-25℃) on shelf. The result showed that strawberries which were retailed at 4℃ with humidification kept the best quality. Its sensory evaluation, weight loss, firmness, relative electric conductivity sugar-acid ratio and Vc content were 7.8, 0.96%, 13.33 N, 39.64%, 15.00, 105.50mg/100 g respectively after 2 days retailing.6.Effects of different home preservation methods on quality of strawberry were studied. Strawberries which were retailed at 4℃ with humidification for 2d were placed in refrigerator and room temperature for 2d, respectively. The result showed that the sensory evaluation of strawberry in refrigerator and at room temperature were 6.8, 3.8 after 2d, respectively. The former was significant better than the latter on quality of strawberry. The weight loss, firmness, sugar-acid ratio, relative conductivity, vitamin C content of strawberry in refrigerator were 2.13%, 12.6N, 14.05, 43.10%, 91.82mg/100 g after 2d, respectively.To sum up, the suitable cold chain method of strawberry was forced-air cooling to 3℃, storage at 0℃ with 1-MCP+CA treatment, transportation packaged with plastic clamshell containers within carton at 0℃, retailing at 4℃ with humidification and home preservation in refrigerator at 5℃. |
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