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The high consumption of maize tortillas in Mexico has prompted the widespread use of instant maize flours in the food industry, lowering the fibre and calcium contents in tortillas compared to the traditional nixtamal process. The inclusion of food sources such as cladodes could improve the nutritional value of maize tortillas. The aim of this study was to assess the physicochemical (rheology, puffing, rollability, and colour) and nutritional (chemical composition and in vitro intestinal bioaccessibility of calcium) parameters of maize tortillas made from commercial flour, substituted with 3% and 6% cladode flour. Partial substitution of maize flour with dried cladodes proved to be a good alternative to conventional tortillas both from a sensorial and a physical point of view. An improved rheological behaviour was observed in the dough, in addition to good puffing and rollability characteristics and an attractive colour of maize tortillas. The substitution of 6% maize flour with dried cladodes increased soluble fibre and calcium contents, and improved calcium intestinal absorption (bioaccessibility 48%), giving a value closer to that of traditional nixtamal maize tortillas. The introduction of cladode-supplemented instant maize flours on the market could help improve the fibre and calcium intake –and thus the health status– of the Mexican population. [ABSTRACT FROM AUTHOR]

Abstract: The young stems of Opuntia spp., known as cladodes are widely consumed in Mexico, and appreciated for their high content of fiber and beneficial effects in the metabolism of glucose. Since, boiling process is often applied to these vegetables, the objective of this study was to evaluate the influence of this process on the chemical composition, antioxidant capacity and physicochemical properties of two cladode cultivars. The components most affected were the soluble compounds (sugars, minerals, vitamin C and phenolics), while proteins, lipids and fiber showed a high retention. The losses of phytochemicals were related to the decrease of the antioxidant capacity. Cladodes presented good hydration properties inducing a non-Newtonian, pseudoplastic and thixotropic behavior in suspension. Heat treatment reduced the viscosity and gel consistency and these changes affected the physiological properties related to capacity of cladodes to hold glucose and control the glycemic response. The intake of these compounds and the estimation of some properties may be overestimated when data of raw sources are used. Further research to determine boiling conditions to minimize the changes on composition of these vegetables is necessary. [Copyright &y& Elsevier]

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, 25min; 80% for 3, 5, 8, 10, 15 and 25min) 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 25min significantly reduced the microbial count in 15 and 25min, 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. [Copyright &y& Elsevier]