Effect of storage temperature on physical-chemical and microbiological characteristics of beetroot juice

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Although beetroot is a rich source of nutrients: vitamin, minerals, fibres, protein, among others, very few beetroot products have been developed. However, beetroot is very perishable like fruits and vegetables. The objective of this study was to determine the effect of temperature and storage duration on physical, chemical and microbiological changes in beetroot juice during storage period of 28 days at 4 ? and at 24 ?. The beetroot juice was developed and immediately stored at 4 ? and at 24 ?. The physico-chemical parameters such as pH, titratable acidity (TA), turbidity, colour, total soluble solids (TSS) and microbiological parameters such as total aerobic count (TAC), total coliform count, and yeast were determined in both samples at 4 ? and 24 ?. All data were analysed using one-way analysis of variance (ANOVA). Least significant difference between means was determined at the level of P ? 0.05. The overall results of this study showed high pH (3.46) in beetroot juice stored at 24 ? compared to the same juice with pH (4.6) at 4 ? ; high total acidity of 0.6% was observed in juice stored at 24 ? ; high turbidity of (19.68 NTU) was found in juice stored at 4? ; the slight change was observed for TSS for both beetroot juices at 4 and 24? ( 12.5 °brix and 12.7 ºbrix respectively ); the slight significant change (P ? 0.05) was also observed for colour of both juices at 4 and 24? (0.7 %Abs and 0.6 %Abs respectively). The TAC for both juices at 4 and 24? were 38.38 and 69.32 CFu/ml respectively. The results of this study showed effect of low temperature on growth TAC during storage (P ? 0.05). The low yeast at 4? (45.81 CFU/ml) and high yeast 62.89 CFU/ml were observed but the effect was not statistically significant at P ? 0.05. Therefore, this study clearly shows the possibility of processing beetroot juice and its suitable storage temperature.