Effect of heat treatment on the storage stability of low calorie milk drinks

An investigation on the effect of ultrasonication and microfiltration processing on the quality of king coconut (Cocos nucifera var. aurantiaca) water compared to minimal and thermal processing

The study aimed to investigate the effect of thermal and non-thermal processing on the physicochemical, microbial, and sensory characteristics of king coconut water. King coconut water samples were subjected to ultrasonication (50 kHz, 30 min at 35 °C), microfiltration (0.5 µm), and thermal treatments (at 90 °C for 10 min) with sodium metabisulfite (0.1 g/L) except the fresh sample (control). Samples were tested for physiochemical, microbial, and sensory parameters. Storage studies were conducted at 4 °C for 28 days. pH, titratable acidity, and total sugar of all treated samples were within the Sri Lankan Standard (SLS) limit (4.6-5.5, 0.07-0.1%, 4.1-6.5%, respectively) during the 28 days of storage. Sodium metabisulfite addition was significant in lowering the browning index. Antioxidant and phenolic contents of microfiltered and ultrasonicated samples varied between 49%-65% and 2.5-2.8 GAE mg/100 mL, respectively, during 4 weeks of storage, which was significantly higher compared to the heat-treated samples. Sensory evaluation scored the lowest attribute values for thermally treated samples. Microbial analyses indicated that microfiltered and ultrasonicated king coconut water remained safe for consumption for up to 4 weeks. Ultrasound and microfiltration, with the integration of sodium metabisulfite, were identified as effective methods for processing king coconut water while preserving its wholesome properties.

Total carotene content and quality characteristics of pumpkin flavoured buffalo milk

As per the World Health Organization (WHO) and Global Hunger Index, the incidence of malnutrition and Vitamin-A deficiency in preschool-age children is higher in South-East Asian countries. Therefore, this study was envisaged to formulate value-added flavoured buffalo milk and to carry out the sensory evaluation, nutritional analysis, storage characteristics and total carotene content of the developed product. Flavoured buffalo milk was prepared by incorporation of Cucurbita pepo (Pumpkin) pulp and ground sugar at a concentration of 15% and 10%, respectively. The formulation was found preeminent by panellists and then subjected to nutritional analysis and storage studies at room temperature following "in bottle heat treatment". Nutritional analysis revealed that the protein, fat, total carbohydrates, total ash and moisture content of pumpkin flavoured buffalo milk were 3.07%, 5.21%, 12.63%, 0.61% and 78.48%, respectively. The storage study of flavoured buffalo milk showed a significantly (p < 0.05) declined score in colour and appearance as well as flavour only after day 90. The overall acceptability score also declined significantly (p < 0.05) after day 60 of storage. Though the sensory score declined gradually during the storage period, the product was liked by the panellist even till day 180. The carotene content of pumpkin flavoured buffalo milk was 1.2 mg/100 g at day 0 and it decreased significantly as storage prolongs. The nutritional components were not affected significantly during the 180 days storage period. Standard plate counts, coliform counts as well as yeast and mould counts were not detected during storage of pumpkin flavoured buffalo milk.