Characteristics of orange-whey fermented beverages

Abstract

The aim of the present work was to determine the populations of ABT culture microorganisms in orange and orangewhey drinks after fermentation and during 28-day storage. The evaluation involved fermented fruit drinks without whey or with added acid or sweet (rennet) whey. The Streptococcus thermophilus and Bifi dobacteria counts were initially 3.5×105-8.3×105 CFU cm-3 and 2.4×106-5.9×106 CFU cm-3, respectively, and did not increase during fermentation. However, an increase was observed in the Lb. acidophilus count, which amounted to 3.0×106-2.4×107 CFU cm-3 after fermentation. During storage, the Str. thermophilus and Lb. acidophilus counts remained constant, but that for Bifi dobacteria fell to 103 CFU cm-3 after 28 days. Bacteria survivability was higher in drinks containing whey than in non-whey orange drinks. In 100 cm3, antioxidant activity against ABTS/DPPH radicals varied between 260 and 550 μmol TE; vitamin C content was in the range of 15.7-17.6 mg; polyphenols were 26.6-34.4 mg (+)catechin. In the sensory evaluation the best results were obtained for non-whey drinks and those containing 50% acid whey.