Effect of brewing conditions on antioxidant properties of rosehip tea beverage: study by response surface methodology

Berries as Foods: Processing, Products, and Health Implications

Berries are highly regarded as flavorful and healthy fruits that may prevent or delay some chronic diseases attributed to oxidative stress and inflammation. Berries are low in calories and harbor diverse bioactive phytochemicals, antioxidants, dietary fibers, and vitamins. This review delves into the main characteristics of fresh berries and berry products as foods and the technologies associated with their production. The main effects of processing operations and related variables on bioactive components and antioxidants are described. This review critically discusses why some health claims based on in vitro antioxidant data and clinical studies and intervention trials are difficult to assess. The review suggests that the beneficial health effects of berries are derived from a multifactorial combination of complex mixtures of abundant phenolic components, antioxidants, and their metabolites acting synergistically or additively with other nutrients like fibers and vitamins and possibly by modulating the gut microbiota.

Cocoa Shell Infusion: A Promising Application for Added-Value Beverages Based on Cocoa's Production Coproducts

The cocoa shell (CS) is being incorporated into different food products due to its recognized content of bioactive compounds. In the case of cocoa shell infusions (CSI), the bioactive compounds that manage to be transferred to the infusion have yet to be clearly known, i.e., what is really available to the consumer. In this study, CS was obtained from toasted Colombian Criollo cocoa beans. Three particle sizes (A: >710 µm; B: >425 and <710 µm; C: <425 µm) were evaluated in the CSI, which was traditionally prepared by adding CS to hot water (1%). The decrease in particle size increased the antioxidant capacity (DPPH and ABTS) and the total phenolic compounds. A significant effect (p < 0.05) both of the particle size and of the temperature of tasting was found on some sensory attributes: greater bitterness, acidity, and astringency were due to the greater presence of epicatechin, melanoidins, and proanthocyanidins in the smaller particle sizes. The analysis of the volatile organic compounds showed that the CSI aroma was characterized by the presence of nonanal, 2-nonanone, tetramethylpyrazine, α-limonene, and linalool, which present few variations among the particle sizes. Moreover, analysis of biogenic amines, ochratoxin A, and microbial load showed that CSI is not a risk to public health. Reducing particle size becomes an important step to valorize the functional properties of CS and increase the quality of CSI.

Effect of In Vitro Digestion on the Phenolic Content of Herbs Collected from Eastern Anatolia

Phenolic compounds in herbs have high antioxidant activities, and their consumption as functional foods may impact human health positively. The main objective of this study was to investigate the total phenolic (TPC) and total flavonoid (TFC) contents as well as total antioxidant capacities (TAC) of bioactive compounds in various infusions prepared by herbs collected from the Bingöl region of Turkey during in vitro gastrointestinal digestion. According to the results, while the highest TPC (5836 ± 373 mg GAE/100 g dw), TFC (2301 ± 158 CE/100 g, dw), and TAC (1347 mg TE/100 g dw) were obtained with Anchusa azurea Mill. species, Crataegus orientalis exhibited the lowest values (863 ± 24 mg GAE/100 g dw, 242 ± 23 CE/100 g dw, 735 ± 47 mg TE/100 g dw, respectively). Gallic acid and chlorogenic acid were the most common phenolic compounds in the infusions. In detail, the highest gallic acid was found in E. spectabilis M. Bieb (27.3 ± 0.9 mg/100 g of dw) and the highest chlorogenic acid was observed in F. elaeochytris (919.2 ± 35.7 mg/100 g of dw). After in vitro gastrointestinal digestion, the highest bioaccessibility values of TPC and TFC were determined as 0.6- and 3-fold of the values observed in undigested C. orientalis, respectively. Besides, C. orientalis Pall. had the highest bioaccessibility of TAC according to the DPPH (6.7-fold increase) and CUPRAC (9.7-fold increase) assays. It can be concluded that the use of these medicinal herbs in human dietary intake due to their high bioactive compounds even after digestion can improve nutritional value and contribute to human health.

Reducing the Flocculation of Milk Tea Using Different Stabilizers to Regulate Tea Proteins

The regulation of flocs derived from polyphenol–protein formation in milk tea has not been fully explored. In this study, the flocculation of milk tea was regulated by adding 10 kinds of stabilizers with different characteristics. The stability coefficient and centrifugal precipitation rate were used as indexes. The optimal concentration ratio of the complex stabilizer was identified using the response surface methodology (RSM), being 0.04% for Arabic gum, 0.02% for β-cyclodextrin and 0.03% for Agar. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the characteristics of different stabilizers in milk tea, and our findings were as follows: (1) The relative strength of the peaks in different stable systems was different. The absorption peaks were mainly near the wave numbers 3376 cm−1, 2928 cm−1, 1655 cm−1, 1542 cm−1, 1408 cm−1, 1047 cm−1 and 925 cm−1. (2) The milk tea system was an amorphous structure. The diffraction peak of the composite system was observed to be about 20°. The crystallinity of the milk tea in the compound group was 33.16%, which was higher than that of the blank group (9.67%). (3) The compound stabilizer reduced flocculation, and the stabilizing agents improved the surface order of milk tea. These results indicate that the combination of polysaccharide stabilizers (Arabic gum and agar) and oligosaccharide stabilizers (β-CD) in certain proportions can regulate the flocculation of milk tea and improve its stability. The potential research avenues involving polyphenol–protein complex instability systems and their applications in food development are expanded by this work.

From Herbal Teabag to Infusion—Impact of Brewing on Polyphenols and Antioxidant Capacity

Herbal teas, which are a rich and diverse source of polyphenols, have been widely consumed due to their association with various health benefits. Preparation techniques can significantly affect the level of polyphenols in a cup of tea. Thus, this study investigated the impact of different preparation techniques, including brewing time in hot water, microwave-assisted extraction with cold and hot water (cold and hot MAE) for both radiation time and power, and laboratory testing condition on extractability of polyphenols in infusion from a teabag. The results showed that brewing time using hot water significantly affected the extractability of polyphenols and antioxidant activity. Cold and hot MAE conditions also significantly affected the extractability of polyphenols and antioxidant activity from a teabag infusion. Hot brewing at 7 min and cold MAE at full power with second boiled (1.93 min on and 1 min off radiation) are recommended for the preparation of herbal tea from a teabag, as these conditions had comparable extractability of polyphenols and antioxidant activity in comparison with other preparation techniques. There are over 20 major chromatogram peaks, of which 7 were identified as gallic acid, catechin, caffeic acid, ferulic acid, epicatechin gallate, quercetin, and kaempferol, revealing potential health benefits of this herbal tea.

Bioavailability of Rosehip (Rosa canina L.) Infusion Phenolics Prepared by Thermal, Pulsed Electric Field and High Pressure Processing

In this study, the in vitro bioavailability of rosehip infusion phenolics, mainly catechin, as a response to conventional and non-thermal treatments by combining gastrointestinal digestion and a Caco-2 cell culture model, was investigated. After application of thermal treatment (TT, 85 °C/10 min), high pressure (HPP, 600 MPa/5 min) or pulsed electric field (PEF, 15 kJ/kg) processing, all samples were subjected to simulated gastrointestinal digestion. Then, the amount of maximum non-toxic digest ratio was determined by the cytotoxicity sulforhodamine B (SRB) assay. Next, Caco-2 cells were exposed to 1:5 (v/v) times diluted digests in order to simulate the transepithelial transportation of catechin. Results showed that non-thermally processed samples (5.19 and 4.62% for HPP and PEF, respectively) exhibited greater transportation across the epithelial cell layer compared to than that of the TT-treated sample (3.42%). The present study highlighted that HPP and PEF, as non-thermal treatments at optimized conditions for infusions or beverages, can be utilized in order to enhance the nutritional quality of the final products.

The Impact of Dietary Supplementation of Whole Foods and Polyphenols on Atherosclerosis

The purpose of this review is to highlight current research on the benefits of supplementation with foods with a diverse polyphenol composition, including fruits, vegetables, nuts, grains, oils, spices, and teas in blunting atherosclerosis. We searched PubMed for publications utilizing whole food or polyphenols prepared from whole foods in Apolipoprotein E (ApoE) or Low-Density Lipoprotein Receptor (LDLR) knockout mice, and identified 73 studies in which plaque was measured. The majority of the studies reported a reduction in plaque. Nine interventions showed no effect, while three using Agaricus blazei mushroom, HYJA-ri-4 rice variety, and safrole-2', 3'-oxide (SFO) increased plaque. The mechanisms by which atherosclerosis was reduced include improved lipid profile, antioxidant status, and cholesterol clearance, and reduced inflammation. Importantly, not all dietary interventions that reduce plaque showed an improvement in lipid profile. Additionally, we found that, out of 73 studies, only 9 used female mice and only 6 compared both sexes. Only one study compared the two models (LDLR vs. ApoE), showing that the treatment worked in one but not the other. Not all supplementations work in both male and female animals, suggesting that increasing the variety of foods with different polyphenol compositions may be more effective in mitigating atherosclerosis.

Herbal infusions and health

Purpose

Increasingly, interest in and the uptake of herbal infusions has advanced, namely, owing to their bioactive properties and potential links to health. Given this, the purpose of the present review was to collate evidence from human trials for five popular herbal infusions.

Design/methodology/approach

The systematic review comprised ten human trials (560 participants), investigating inter-relationships between herbal infusions consumption and health. Only human studies involving German chamomile (Matricaria chamomilla L. Asteraceae), ginger (Zingiber officinale Roscoe Zingiberaceae), lemon balm (Melissa officinalis L. Lamiaceae), peppermint (Mentha x spicata L. Lamiaceae)/spearmint (Mentha spicata L. Lamiaceae) and rosehip (Rosa canina L. Rosaceae) teas were included in the present paper.

Findings

Most herbal infusions serve as a good source of flavonoids and other polyphenols in the human diet. Studies included in this paper indicate that herbal infusions (1-3 cups tended to be drank daily; infusion rates up to 15 min) could benefit certain aspects of health. In particular, this includes aspects of sleep quality and glycaemic control (German chamomile), osteoarthritic stiffness and hormone control (spearmint), oxidative stress (lemon balm) and primary dysmenorrhea (rosehip).

Research limitations/implications

Ongoing research is needed using homogenous herbal infusion forms, brewing rates and volumes of water to further reinforce these findings. In the meantime, herbal infusions could provide a useful supplementary approach to improving certain aspects of well-being.

Originality/value

The present paper collates evidence from human trials for five popular herbal infusions.