Cruz C.N., Pérez C. G., Zafra R.Q., Delgado O.L., Alanís G.E., Ramírez M.E. (2013). Ultrasound Processing on Green Cactus Pear (Opuntia ficus Indica) Juice: Physical, Microbiological and Antioxidant Properties. J Food Process Technol. 4: 267-272.
"In Mexico, the consumption of green cactus pear fruit it is usually eaten fresh. This fruit could be a naturalproduct with a rapid presence in the market, especially if the production technologies are optimized. The aim of thepresent study was to evaluate the effect of ultrasound (amplitudes 40, 60 and 80% at different times 10, 15 and 25min) in the quality (pH, Brix, stability), microbial growth, phenolic content, ascorbic acid and the antioxidant activityof green cactus pear juice. We found that application of a greater amplitude and time of ultrasound (higher 60% 15min) significantly decreased the microbial load. Treatment >15 min presented higher total solid soluble (Brix) withvalues of 13.00 - 13.40 Brix. Treatment 60% 15 min, 80% 8, 15 and 25 min showed better physical stability (lower %settled solids) around 16.93%-19.41%. Appreciable amount of bioactive compounds was found mainly in treatmentat 80% 25 min in total phenolic contents, while ascorbic acid was the treatments at 60% 25 min and 80% 10 min,preserving the antioxidant activity present in the juice mainly treatments >15 min in ABTS. The amplitude and time ofultrasound applied in the juice might allow the suitable conditions of conservation for industrial use."