Abstract:The objective of this study was to mix beet juice and orange juice in two proportions (1:1 and 1:2 v/v), evaluate their physicochemical stability and antioxidant activity during storage (4 • C for 30 days), and evaluate their acceptance by consumers. Beet juice (with or without pasteurization) and pasteurized orange juice were used as controls. The presence of orange juice contributed to the pH, betacyanin, betaxanthin, and antioxidant capacity stabilities during storage, whereas the presence of beet improved the color stability. The mixed juices showed high total phenolic compounds (484-485 µg gallic acid/mL), DPPH scavenging capacity µg Trolox/mL), and ABTS (1854-1840 µg Trolox/mL), as well as better sensory acceptance than the pasteurized beet juice. However, the mixed juices had a more significant reduction in the ascorbic acid content (completely lost at 15 days of storage) than the pasteurized orange juice (25% reduction at 30 days). The beet and orange mixed juice is an alternative functional beverage that can contribute to an increase in the consumption of beet and orange.

Purpose The purpose of this study was to evaluate beet and orange mixed juices added with lyophilized Lactobacillus acidophilus probiotic culture. Design/methodology/approach Two formulations of probiotic beet and orange mixed juices (1:1 e 1:2 v/v) were prepared, stored at 4°C for 28 days and were evaluated for probiotic survival, physicochemical stability, antioxidant activity and sensory acceptance. The probiotic culture was added in a lyophilized form and was not propagated in culture media or juice. Findings Physicochemical characteristics (pH, titratable acidity, total soluble solids and color) and antioxidant activity showed no undesirable alterations during storage. The number of probiotics followed established minimum requirement for probiotic foods (109 CFU/200mL) during the 28 days of storage. The juices showed good sensory acceptance and purchase intention, especially regarding the color of the product. Practical implications The beet and orange mixed juices are suitable carriers for L. acidophilus with a shelf life of at least 28 days at 4°C. Originality/value Direct addition of the probiotic culture could result in high probiotic survival in mixed juices, dispensing the propagation step.

Purpose The purpose of this study is to evaluate the effect of the probiotic addition (Lactobacillus paracasei ssp.) on the physicochemical characteristics and antioxidant capacity of white grape juice during refrigerated storage (4°C/28 days). This paper also aims to evaluate the survival of the probiotic culture in the product and under simulated gastrointestinal conditions. Design/methodology/approach Two formulations of white grape juices were evaluated, one with 2 per cent of probiotic culture addition and the other of pure juice. Findings The addition of probiotic culture resulted in products with a darker-reddish coloration (L* = 30.6-30.8 and a* = 0.6-0.9) and a lower content of total phenolic compounds (599-697 µg EAG mL−1) (p = 0.05). However, it improved the color stability and maintained the antioxidant activity 1,1-diphenyl-2-picrylhydrazyl (p > 0.05). The viability of the probiotic culture (>109 colony forming unit · 200 mL−1) in the juice was maintained during 21 days of storage, but in simulated gastrointestinal conditions, the functional properties could be guaranteed during the 28 days of refrigerated storage. Practical implications The white grape juice is a suitable medium for incorporation of Lactobacillus paracasei. Originality/value The survival of the probiotic cultures to the simulated gastrointestinal tract may be significant, even if the product does not have the recommended minimum counts.