Effects Of Storage Temperatures And Packaging Combinations On The Storage Quality Of Fresh Yacon

Abstract


A factorial combination of 2 storage temperatures (room temperature and 10ºC) and 3 packaging (unpacked control/open, modified atmosphere packaging using LDPE with 8pinpricks asMAP1, and modified atmosphere packaging using LDPE with 8 perforations as MAP2) were used during storage of yacon tubers. The yacon tubers were evaluated weekly for physical and chemical properties for a period of 14 weeks. Firmness and visual quality of unpacked control yacon rapidly declined during storage at room temperature and at 10°C relative to those under modified atmosphere packaging (MAP). The declinein thevisual qualityofunpacked yacon was mainly due to microbial decay and severe shriveling caused by rapid water loss. Weight loss of yacon was reduced and consequently loss of firmness and shriveling was reduced in MAP, with MAP1 as the most effective, compared to the unpacked yacon under both storage temperatures. Theuse of MAPin yacon underroom temperature foran extended storage period was limited by the development of disease and the occurrence of root sprouts and surface cracks in yacon which reduced its visual quality. The MAP combined with low temperature (10ºC) maintained the physical quality of yacon for aperiod of 12 weeks.

On the other hand, hydrolysis of FOS by fructan exohydrolase occurred during storage leading to a larger amount of fructose, glucose, and sucrose. The lower temperature and MAP used in the study did not suppress the hydrolysis of FOS but merely delayed the onset of rapid FOS conversion. Changes in PPO activity and TPC occurred in response to stress during storage. The antioxidant activity in yacon varied during storage but did not fall below the initial value.

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