Phytochemical characterization of different prickly pear (Opuntia ficus-indica (L.) Mill.) cultivars and botanical parts: UHPLC-ESI-MSn metabolomics profiles and their chemometric analysis.

Prickly pear is an important source of bioactive compounds. However, a comprehensive characterization of the phytochemical profile of its aerial botanical parts, considering genotypic differences, has not been conducted. This study evaluated the phytochemical composition of four botanical parts (fruit pulp and skin, and young and adult cladodes) of six cultivars. Analysis was carried out by using two non-targeted UHPLC-ESI-MSn experimental conditions and assisted with multivariate analysis to facilitate data interpretation. Up to 41 compounds, mainly (poly)phenolic molecules, were identified and quantified, 23 compounds being reported for the first time in Opuntia ficus-indica. Phenolic composition varied significantly depending on the part of the plant. Betalains were detected only in the fruit of a red cultivar. This study provided novel insights in terms of identification of bioactives and thorough characterization of botanical parts of prickly pears. This information may be used for the development of prickly pear-derived products with high levels of bioactive compounds.

Antioxidant properties and chemical characterization of Spanish Opuntia ficus-indica Mill. cladodes and fruits.

BACKGROUND: Recent studies have demonstrated that consumption of Opuntia ficus-indica Mill. has an important positive health benefit, mainly due to antioxidant properties, which justifies this research. This study examined antioxidant activity, organic acid and sugar profile, total phenolic, and physicochemical characteristics of six O. ficus-indica cultivars growing in the Spanish Mediterranean. It should be noted that, in this study, both cladodes (young and adult) and fruits (peel and pulp) were analyzed. RESULTS: The antioxidant activity (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl methods) was higher in fruit peel than in cladodes. The young cladodes presented an important antioxidant activity by the ferric-reducing ability of plasma method as well as a higher total phenolic content (18.90 g gallic acid equivalent per kilogram). High-performance liquid chromatography (HPLC) with diode-array detector analysis revealed the absence of sucrose and the presence of glucose and fructose, which the values were higher in pulp fruits. HPLC with refractive index detector analysis showed that citric, malic, and succinic acids were the main organic acids in all cultivars, with a significant higher content in old cladodes. CONCLUSION: These investigations valorize O. ficus-indica fruits in comparison with cladodes. In general, this plant can be considered as an ingredient for the production of health-promoting food, highlighting mainly in the antioxidant activity and total polyphenols content found in young cladodes and peel fruits. © 2017 Society of Chemical Industry.

Influence of Fermentation with Different Lactic Acid Bacteria and in Vitro Digestion on the Biotransformation of Phenolic Compounds in Fermented Pomegranate Juices.

This study describes the effect of fermentation and the impact of simulated gastrointestinal digestion (SGD) of four fermented pomegranate juices with different lactic acid bacteria (LAB) on the biotransformation of phenolic compounds. The changes of the antioxidant capacity (AOC) and of LAB growth and survival in different fermented juices were also studied. Two new phenolic derivatives (catechin and α-punicalagin) were identified only in fermented juices. During SGD, the AOC increased together with the phenolic derivatives concentration mainly in the juices fermented with Lactobacillus. These derivatives were formed due to the LAB metabolism of the ellagitannins, epicatechin, and catechin after fermentation and during SGD. The FRAP assay performance might be associated with the degradation and biotransformation of catechin. The fermented pomegranate juices with these LAB increased the bioaccessibility of phenolic compounds, ensuring the survival of LAB after SGD, suggesting a possible prebiotic effect of phenolic compounds on LAB.

Pomegranate juice adulteration by addition of grape or peach juices.

BACKGROUND: Pomegranate juice has gained a high reputation for its health properties and consequently is now a highly demanded product. However, owing to the limited production and high price of fresh pomegranates, adulteration of pomegranate juice seems to be happening. Hence it is imperative to establish criteria for detecting adulteration. RESULTS: Addition of grape juice significantly increased the contents of Ca, Mg and Fe and especially tartaric acid and proline and simultaneously decreased the content of K. Addition of peach juice up to 10% (v/v) only resulted in a significant increase in sucrose content. Regarding the volatile composition, adulteration of pomegranate juice with grape juice resulted in significant increases in acetic acid, isoamyl butyrate and especially 1-hexanol and linalool, while adulteration with peach juice resulted in significant increases in butyl acetate, isobutyl butyrate, benzyl acetate and especially isoamyl butyrate. CONCLUSION: The control protocols used in this study can serve as a basis for identification of pomegranate juice adulteration. It is important to highlight that it is necessary to simultaneously analyze and have results from several parameters to conclude that a particular pomegranate juice has been adulterated by mixing with another fruit juice.