Evaluation of quality characteristics of coconut drinks during refrigerated storage

Abstract

In today's fast-paced world, food and beverages need to be preserved by applying innovative processing techniques. The research was carried out to make ready-to-serve beverages from a green coconut, and the impact of vacuum, microwave, and combined vacuum-microwave treatment on those samples was also examined based on physicochemical, microbiological, and sensory quality. Four samples namely fresh, vacuum (at pressure −200mm/Hg or −26.7Kpa at 30 °C for 10 min), microwave (treated at power level 720 W for 10 min at 80 °C temperature), and combined vacuum-microwave treated were prepared, and analyzed for pH, total soluble solids (°Brix), acidity, total sugar, protein, color, mineral content, and microbial load at 5 days intervals during refrigerated storage. In the storing period of coconut drinks, the pH value decreases from (5.08–5.39) to (4.21–3.51) and thus, the acidity increases from (0.08–0.09) to (0.41–0.22) %. The analysis demonstrates that, the lowest amount of total soluble solid (8.04%), total sugar (10.67%), protein (34.25%), potassium (1.43%), calcium (12.93%), magnesium (51.93%), and iron (6.97%) loss were observed in the combined vacuum-microwave treated sample during storage than the other samples. During the time of storing, the lowest color change (15.2 ± 0.59) and the highest overall acceptability (7.80 ± 0.46) were observed in the combined vacuum-microwave treated sample. Moreover, the shelf-life of the combined vacuum-microwave treated sample was greater (25 days) than the other treated and untreated samples. Therefore, the result revealed a considerable effect of the processing treatment on the samples. In conclusion, the combined vacuum-microwave treated sample presumed with superior quality; thus, it is recommended that, combined vacuum-microwave treatment can be used industrially as a novel processing method to produce the best quality and the safest coconut drinks.