Evaluation of refrigeration storage-induced changes in guava-whey drink prepared with whey from buffalo milk

Guava fruit is a rich source of fiber, and vitamins (C, A, & B), while milk whey contains high levels of lactose, α-lactalbumin, and β-lactoglobulin. Blending guava pulp with whey yields a functional drink that may offer health benefits by providing essential nutrients from both sources. We formulated and evaluated the guava whey drink over two months of storage (4 °C) at 10-day intervals. Key parameters analyzed include titratable acidity, vitamin C content, microbial load, protein content, and total soluble solids. Our results indicated that total soluble solids and titratable acidity increased over time, ranging from 7.3 to 22.7 °Brix and 0.34–0.63, respectively. Conversely, ascorbic acid (vitamin C) content and protein levels declined, with ascorbic acid ranging from 16.8 to 14.3 mg/100 g and protein content from 1.06 to 0.20%. Microbial counts, including total plate count (1.93 to 2.53 log CFU/mL), also increased during storage. We concluded that the formulation (F 2 ) with 80% whey and 20% guava pulp provided the most favorable sensory characteristics and was acceptable throughout the entire storage period.