Effects of ultrasound treatment in purple cactus pear (Opuntia ficus-indica) juice

Abstract

Cactus pear (Opuntia ficus-indica) fruit is a berry with a tasty pulp full of seeds that constitutes about 10-15% of the edible pulp. In Mexico, cactus pear is mainly consumed fresh, but also has the potential to be processed in other products such as juice. The objective of this study was to evaluate the effect of different ultrasound conditions at amplitude levels ranging (40% and 60% for 10, 15, 25 min; 80% for 3, 5, 8, 10, 15 and 25 min) on the characteristics of purple cactus pear juice. The evaluated parameters were related with the quality (stability, °Brix, pH), microbial growth, total phenolic compounds, ascorbic acid and antioxidant activity (ABTS, DPPH and % chelating activity) of purple cactus pear juices. The ultrasound treatment for time period of 15 and 25 min significantly reduced the microbial count in 15 and 25 min, without affecting the juice quality and its antioxidant properties. Juice treated at 80% of amplitude level showed an increased of antioxidant compounds. Our results demonstrated that sonication is a suitable technique for cactus pear processing. This technology allows the achievement of juice safety and quality standards without compromising the retention of antioxidant compounds.

Study of the Effect of Thermoultrasound on the Antioxidant Compounds and Fatty Acid Profile from Blackberry (<em>Rubus fruticosus spp</em>) Juice

“…Both treatments increased the antioxidant activity by DPPH, the pasteurized juice showed values of 1320 µmol TE/L, while thermoultrasonicated juice the value was of 2656 µmol ET/L, being more than doubled in comparison to the value obtained for control juice (1147 µmol TE/L). Similar observations were reported by ZafraRojas et al [13] who state that amplitude and time during treatment of ultrasound release antioxidants, and as in other fruits, the total antiradical activity in blackberry juice is the sum of the antiradical activities of all antioxidant compounds in the fruit, such as phenolic compounds, taurine, vitamins, betalains, anthocyanins content, ascorbic acid among others [13]. a-c Different letters in the same line indicate significant difference (p < 0.05) between the juices in the same determination.…”

“…The higher values of antioxidant activity by ABTS and DPPH were in thermoultrasound treatment, this due to the disruption of biological cell walls facilitating the release of their antioxidant compounds [13] ( Table 2). Figure 1 and Table 3 shows the results of the fatty acids contained in the blackberry juice.…”

“…This technology has the potential to pasteurize several foods, as juice beverage through its exposure to high-intensity sound waves, effect that generates physical disruptions and induces chemical reactions on the material to which it is applied [11,12]. Ultrasound allows the preservation of quality parameters such as color, flavor and antioxidant properties and at the same time facilitates the release of bioactive compounds [13]. However, ultrasound alone is not very effective hence, so that combined application of ultrasound and mild temperatures between 50 and 60 °C (called thermoultrasound) to reduce the temperature and/or time of the sterilization process to prevent damage in the product have been used [14,15].…”

Changes in Quality Attributes of Strawberry Purees Processed by Power Ultrasound or Thermal Treatments

“…The apparent increase in the total phenolics content in sonicated strawberry puree can be attributed to the greater disruption of cell walls and subsequent release of the bound phenolic compounds (Zafra-Rojas et al, 2013). In addition, the removal of occluded oxygen from the strawberry puree by sonication was suggested to contribute to this apparent increase in the phenolic compounds (Masuzawa et al, 2000).…”

“…Power ultrasound has been reported to be effective against foodborne pathogens in fruit juices such as orange juice (Valero et al, 2007), mango juice (Santhirasegaram et al, 2013), apple juice (Abid et al, 2013), guava juice (Cheng et al, 2007), and tomato juice (Adekunte et al, 2010). The application of power ultrasound was also found to better preserve the health promoting functional compounds and other quality parameters of purple cactus pear juices (Zafra-Rojas et al, 2013), apple juice (Abid et al, 2013(Abid et al, , 2014, and red raspberry puree (Golmohamadi et al, 2013).There are several publications on ultrasound processing of fruit juices/purees dealing with various aspects such as inactivation of microbes and anthocyanin stability. However, the effects of ultrasound treatment on the quality parameters (viscosity, total pheolics and antioxidant activity) of strawberry puree have not been reported so far.…”