Beverages2016, 2(3), 18; doi:10.3390/beverages2030018 (registering DOI) - published 25 July 2016 Show/Hide Abstract
Abstract: Single cultivar wines made with two different red grape cultivars from AOC Valdeorras (Galicia, NW Spain), Mencia and Alicante Bouschet, were studied with the aim of determining their color and phenolic composition. Two sets of analyses were made on 30 wine samples of 2014 vintage, after malolactic fermentation took place, to evaluate several physicochemical characteristics from these wines related to color and polyphenols. Several parameters related with color and the general phenolic composition of wines (total phenols index, color intensity, hue, total anthocyans, total anthocyanins, colored anthocyanins, chemical age index, and total tannins) were determined by UV-VIS spectrophotometry. Those analyses revealed that Alicante Bouschet wines presented, in general, a higher content of polyphenols and a more intense color than Mencia wines. Using HPLC-DAD, five anthocyanin monoglucosides and nine acylated anthocyanins were identified in both types of wine; each type of wine showed a distinctive anthocyanin fingerprint, as Alicante Bouschet wines contained a higher proportion of cyanidin-derived anthocyanins. Multivariate statistic studies were performed to both datasets to explore relationships among variables and among samples. These studies revealed relationships among several variables considered, and were capable to group the samples in two different classes using principal component analysis (PCA).
Abstract: Potential health benefits of tea consumption are often attributed to the antioxidant activity of polyphenols. Whether steep time, often variable in a real-life situation, makes a biological difference in terms of polyphenol content and antioxidant activity is uncertain. The study objective was to characterize eight popular and commercially available teas for total polyphenol content (TPC) and antioxidant capacity in relation to steep time. Dragonwell (DW), Sencha (S), English Breakfast (EB), Golden Monkey (GM), Green Rooibos (GR), Red Rooibos (RR), Chamomile (C), and Peppermint (P) loose leaf teas were individually steeped in water for 1–10 min at 1 min intervals. TPC increased with longer durations of steep time; however, the majority of polyphenols observed after 10 minutes were extracted in the first 5 min regardless of tea type. After 5 min of steeping, differences (p < 0.05) in TPC were observed across teas (JS~EB~P > DW > GM~GR~RR > C). Different teas also varied in their ability to inhibit the free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) when normalized for polyphenol concentration (1 µg/mL) and there was no effect due to steep time. Predicted antioxidant capacity of teas also demonstrated significant differences among teas after 5 and 10 min. In conclusion, steep time modulates TPC but not the antioxidative capacity of tea polyphenols.
Abstract: Green tea catechins (GTCs) are secondary plant metabolites that have been associated with health benefits in human trials. As such, they have the potential to reduce cardiovascular disease (CVD) risk; however, results are not consistent. This systematic review of the published data assessed the putative effect of GTCs supplementation on anthropometric, blood pressure, and biochemical measures associated with CVD risk. It was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines exploring four major electronic databases (MEDLINE, Cochrane Library, Web of Science, and Scopus). Studies were included if they were published in peer-reviewed journals in English from 1990 until October 2015, and were human double-blind randomized and placebo-controlled trials (RCTs). From 122,428 articles initially identified, after two levels of screening, seven studies met the inclusion criteria. The review revealed consistent and significant (p ≤ 0.05) reductions in body mass index (BMI), blood pressure and plasma lipids; however, this effect would have been less if between-group effects had been considered. The current evidence base also has considerable methodological limitations due to suboptimal statistical methods used in data analyses. Future research efforts must aim to rectify this paucity of evidence with well-designed and well-reported prospective studies.
Abstract: The present work analyzed soy milk prepared from whole dehulled soybeans. The traditional method of soy milk preparation leads to wastage of about 35% of soybean solids in the form of okara, which gets filtered out. In the current study, soy milk was prepared with practically 100% recovery of soybean solids and treated with continuous flow high pressure processing (207 and 276 MPa pressure, 121 and 145 °C exit temperatures, and 0.75 and 1.25 L/min flow rates), and the changes in the physical, chemical, microbial, and sensory properties during 28 days of storage at 4 °C were analyzed. The treated soy milk remained stable for 28 days. There was a significant reduction in the particle size of soybean solids which did not change during storage. The pH of the treated soy milk was significantly lower than the untreated soy milk and it reduced further upon storage. The soy milk was pasteurized with high pressure processing coupled with preheating. No lipoxygenase activity was detected. Compared to commercial samples, there was no significant difference in the astringency, bitterness, or chalkiness of soy milk prepared in the study.
Abstract: Eating habits of western populations are changing due to modern lifestyles. As a result, people are becoming more susceptible to chronic and degenerative diseases. This fact has motivated the food industry to develop functional products that could decrease the incidence of those disorders. It is well known that fruit juices, milk and soymilk possess high concentrations of antioxidant and bioactive substances. Hence, the development of these functional beverages is a potential way to take advantage of their nutritional properties and exotic flavors that could attract the interest of consumers. At the same time, application of the right preservation treatment is of high relevance in order to obtain safe products with convenient shelf life and high concentration of health-related compounds. This fact represents a great challenge that scientists and technologists are currently facing. Today, novel preservation processes such as high hydrostatic pressure (HHP), high intensity pulsed electric fields (HIPEF) and ultrasound (US), among others, are being evaluated as an alternative to heat pasteurization, obtaining promising results. Hence, this review gathers the most relevant information about the development of mixed beverages containing fruit juices and milk or soymilk. Furthermore, the advantages and drawbacks of the application of non-thermal treatments for functional beverages’ preservation with high content of bioactive compounds are also mentioned.
Abstract: Tea has been consumed for thousands of years and is an integral part of people’s daily routine, as an everyday drink and a therapeutic aid for health promotion. Consumption of tea has been linked to a sense of relaxation commonly associated with the content of the non-proteinogenic amino acid theanine, which is found within the tea leaves. The aim of this review article is to outline the current methods for synthesis, extraction and purification of theanine, as well as to examine its potential benefits related to human health. These include improvements in cognitive and immune function, cancer prevention, reduced cardiovascular risk and its potential usefulness as a functional food product.