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.

The genus Opuntia embraces different species of cactus, and many of them produce acid fruits known as xoconostle, which are considered valuable vegetable foods in Latin America. Xoconostle fruit contains an edible thick-acid-freshly mesocarp, and seeds that are considered as by-products. Given the high potential of its use and consumption, and the lack of information about its detailed chemical composition and bioactive compounds, the aim of this study was to evaluate the nutritional and antioxidant properties of pulp and seeds of two highly consumed commercial cultivars of xoconostle fruits (Opuntia joconostle F.A.C. Weber ex Diguet, cv. Cuaresmeño, and Opuntia matudae Scheinvar, cv. Rosa).This investigation shows that the pulp of the studied xoconostle cultivars had an appreciable amount of soluble fiber and antioxidant compounds such as ascorbic acid, while the seeds are a source of fiber, phenolics, flavonoids, PUFAs and tocopherols (specially γ-tocopherol), which provide a good antioxidant capacity. In the light of these results, xoconostle fruits should be considered of great interest for either promoting the conventional consumption, and also as sources of bioactive compounds for the addition to other food products, so that all the nutrients present are fully used, instead of being discarded.

The objective of this study was to evaluate changes in color, betalain content, browning index, viscosity, physical stability, microbiological growth, antioxidant content and antioxidant activity of purple cactus pear juice during storage after thermoultrasonication at 80% amplitude level for 15 and 25 min in comparison with pasteurized juice. Thermoultrasound treatment for 25 min increased color stability and viscosity compared to treatment for 15 min (6.83 and 6.72 MPa, respectively), but this last parameter was significantly lower (p<0.05) compared to the control and pasteurized juices (22.47 and 26.32 MPa, respectively). Experimental treatment reduced significantly (p<0.05) sediment solids in juices. Total plate counts decreased from the first day of storage exhibiting values of 1.38 and 1.43 logCFU/mL, for 15 and 25 min treatment, respectively. Compared to the control, both treatments reduced enterobacteria counts (1.54 logCFU/mL), and compared to pasteurized juice decreased pectinmethylesterase activity (3.76 and 3.82 UPE/mL), maintained high values of ascorbic acid (252.05 and 257.18 mg AA/L) and antioxidant activity (by ABTS: 124.8 and 115.6 mg VCEAC/100 mL; and DPPH: 3114.2 and 2757.1 μmol TE/L). During storage thermoultrasonicated juices had a minimum increase in pectinmethylesterase activity (from day 14), and exhibited similar total plate counts to pasteurized juice. An increase of phenolic content was observed after 14 days of storage, particularly for treatment at 80%, 25 min, and an increase in antioxidant activity (ABTS, DPPH) by the end of storage.

The genus Opuntia embraces different species of cactus, and many of them produce acid fruits known as xoconostle, which are considered valuable vegetable foods in Latin America. Xoconostle fruit contains an edible thick-acid-freshly mesocarp, and seeds that are considered as by-products. Given the high potential of its use and consumption, and the lack of information about its detailed chemical composition and bioactive compounds, the aim of this study was to evaluate the nutritional and antioxidant properties of pulp and seeds of two highly consumed commercial cultivars of xoconostle fruits (Opuntia joconostle F.A.C. Weber ex Diguet, cv. Cuaresmeño, and Opuntia matudae Scheinvar, cv. Rosa).This investigation shows that the pulp of the studied xoconostle cultivars had an appreciable amount of soluble fiber and antioxidant compounds such as ascorbic acid, while the seeds are a source of fiber, phenolics, flavonoids, PUFAs and tocopherols (specially γ-tocopherol), which provide a good antioxidant capacity. In the light of these results, xoconostle fruits should be considered of great interest for either promoting the conventional consumption, and also as sources of bioactive compounds for the addition to other food products, so that all the nutrients present are fully used, instead of being discarded.

There is a lack of information on the potential use of xoconostle cultivars as sources of antioxidants for food, pharmaceutical and colorant industries. The aim of this study was to provide a phytochemical characterization and antioxidant activity evaluation of Opuntia matudae Scheinvar cv. Rosa by-products (epicarp and endocarp mucilage's), in order to evaluate their interest as sources of functional ingredients for human or animal foods. These by-products showed a high content in glucose, citric and linoleic acids, tocopherols, and isorhamnetin-O-(di-deoxyhexosyl-hexoside) (mainly in epicarp), and presented relevant antioxidant properties. The obtained results support the use of O. matudae Scheinvar cv. Rosa agro-industrial by-products as functional food ingredients, namely for antioxidant-enriched formulations, instead of being discarded.

The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5 min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5 min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5 min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected.

The 25 kDa subunit of the Clevage Factor Im (CFIm25) is an essential factor for messenger RNA polyadenylation in human cells. Therefore, here we investigated whether the homologous protein of Entamoeba histolytica, the protozoan responsible for human amoebiasis, might be considered as a biochemical target for parasite control. Trophozoites were cultured with bacterial double-stranded RNA molecules targeting the EhCFIm25 gene, and inhibition of mRNA and protein expression was confirmed by RT-PCR and Western blot assays, respectively. EhCFIm25 silencing was associated with a significant acceleration of cell proliferation and cell death. Moreover, trophozoites appeared as larger and multinucleated cells. These morphological changes were accompanied by a reduced mobility, and erythrophagocytosis was significantly diminished. Lastly, the knockdown of EhCFIm25 affected the poly(A) site selection in two reporter genes and revealed that EhCFIm25 stimulates the utilization of downstream poly(A) sites in E. histolytica mRNA. Overall, our data confirm that targeting the polyadenylation process represents an interesting strategy for controlling parasites, including E. histolytica. To our best knowledge, the present study is the first to have revealed the relevance of the cleavage factor CFIm25 as a biochemical target in parasites.

Seed oils from two Mexican varieties of cactus pear (green: Opuntia albicarpa and red: Opuntia ficus indica) were extracted with different solvents (hexane, ethanol, and ethyl acetate) to evaluate their antioxidant activity. The seed oil with higher antioxidant activity was selected to evaluate antimicrobial activity. The fatty acid profile was analyzed by gas chromatography-mass spectrometry (GC-MS). Oil from green cactus pear seeds obtained with ethanol and ethyl acetate exhibited higher antioxidant activity (p<0.05) of 323 and 316 μmol TE/20 mg (p < 0.05), respectively, compared to red cactus pear seed oil (≈274 and 247 μmol TE/20 mg with ethyl acetate and ethanol, resp.). The oil obtained with ethanol and higher antioxidant activity was used to determine the antimicrobial activity. Both cactus pear oils produced a microbial inhibition zone in most of the microorganisms evaluated, particularly Saccharomyces cerevisiae which had similar diameter (38–40 mm). The oil fatty acids profiles of both varieties were similar and exhibited a high content of linoleic acid, while two fatty acids (linolenic and behenic) found in red cactus pear were not observed in the green variety.