Storage studies on the bulk packed buffalo whole milk powder in HDPE bags: browning changes.

摘要

Dried buffalo milk was bulk packed in high density polyethylene (HDPE) bags and stored at a set temperature of 20degC or a variable ambient temperature (22-38degC) for 12 months. The total hydroxymethylfurfural (HMF) content of fresh dried milk samplesranged from 3.15 to 3.46 mum/100 g and it increased significantly during storage. The average total HMF contents were 14.68 and 20.74 mum/100 g after 12 months storage at 20 and 22-38degC, respectively. The development of off-flavour coincided with a suddenincrease in HMF content. The changes in HMF showed a highly significant inverse relationship with organoleptic scores during storage (r = -0.91). The changes in free HMF were very small during storage. The total reducing capacity ranged from 1.42 to 1.60mg cysteine HCl/g. Development of off-flavour coincided with a sudden increase in total reducing value. During storage, the number of free sulfhydryl groups decreased; however, this change was not correlated with flavour scores. The initial colour indexranged from 0.134 to 0.141. The average colour index at the end of 12 months was 0.19 at 20degC and 0.21 at 22-38degC.