The objective of the present study was to determine the effect of the application of a nanoemulsion made of orange essential oil and Opuntia oligacantha extract on avocado quality during postharvest. The nanoemulsion was applied as a coating in whole fruits, and the following treatments were assessed: concentrated nanoemulsion (CN), 50% nanoemulsion (N50), 25% nanoemulsion (N25) and control (C). Weight loss, firmness, polyphenol oxidase (PPO) activity, total soluble solids, pH, external and internal colour, total phenols, total flavonoids, antioxidant activity by 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), while the structural evaluation of the epicarp was assessed through histological cuts. Significant differences were found (p < 0.05) among the treatments in all the response variables. The best results were with the N50 and N25 treatments for firmness and weight loss, finding that the activity of the PPO was diminished, and a delay in the darkening was observed in the coated fruits. Furthermore, the nanoemulsion treatments maintained the total phenol and total flavonoid contents and potentiated antioxidant activity at 60 days. This histological study showed that the nanoemulsion has a delaying effect on the maturation of the epicarp. The results indicate that using this nanoemulsion as a coating is an effective alternative to improve the postharvest life of avocado.
Consumers demand so-called natural in which additive and antioxidant preservatives are from natural origin. Research focuses in using extracts from plants and fruits that are rich in bioactive compounds such as phenolics and betalains, but these are also prone to interact with proteins and are exposed to suffer degradation during storage. In this work, we developed a fortified yogurt with the addition of betalains and polyphenols from cactus pear extract encapsulated in a multiple emulsion (ME) (W1/O/W2). Different formulations of ME were made with two polymers, gum arabic (GA) and maltodextrin (MD) and with the best formulation of ME four types of yogurt were prepared using different % (w/w) of ME (0%, 10%, 20% and 30%). Bioactive compounds, antioxidant activity, color and lactic acid bacteria (LAB) were analyzed in the different yogurts over 36 days of shelf life. Furthermore, in vitro simulated digestion was evaluated. The yogurts had significant (p < 0.05) differences and the ME protected the bioactive compounds, activity of antioxidants and color. The ME did not affect the viability of LAB during 36 days of storage. The in vitro digestion showed the best bioaccessibilities of antioxidant compounds with the yogurts with ME.
Acid cactus fruits “xoconostle” have been used since the pre-Columbian period as a treatment against diverse diseases. In this study, bioactive compounds (phenols and flavonoids) and the in vitro inhibition effect against α-amylase and α-glucosidase were evaluated. Four different extracts of cactus acid fruits were prepared from (1) endocarp, (2) mesocarp, (3) pericarp and (4) whole fruit (WFE). The results showed significant differences (p < 0.05) between extracts. Pericarp extracts had 2.23 ± 0.01 mg of gallic acid equivalents per gram GAE/g of phenol content and 0.84 ± 0.14 mg quercetin equivalents per gram QE/g flavonoid content, while WFE presented 1.52 ± 0.04 mg GAE/g and 0.84 ± 0.14 mg QE/g; however, the inhibition of α-amylase and α-glucosidase were higher with WFE. It was found by using 25 mg/mL of WFE an α-amylase inhibition of 63. ± 1.53% and with 30 mg/mL of WFE an α-glucosidase inhibition of 46.5 ± 1.45% after simulated intestinal conditions. The WFE could be used as a therapeutic strategy in controlled diets of diabetic patients due to its low cost, natural origin, and effect after simulated intestinal conditions.