Effect of Fuzhuan brick-tea addition on the quality and antioxidant activity of skimmed set-type yoghurt

Tea and Citrus maxima complex induces apoptosis of human liver cancer cells via PI3K/AKT/mTOR pathway in vitro

Objective

In this study, black tea and Citrus maxima (BT-CM), yellow tea and C. maxima (YT-CM), green tea and C. maxima (GT-CM) as subjects, the active ingredient content and antioxidant activity of three tea and C. maxima (T-CM) were analyzed. The effects of three T-CMs on apoptosis of liver cells in vitro and its mechanism were further explored.

Methods

National standard method and HPLC were used for active ingredient analysis. MTT, cell flow cytometry and Western blot were used to analyze the effects of three T-CMs on cell proliferation, apoptosis, and its underlying molecular mechanism.

Results

The content of tea polyphenols, free amino acids, ratio of polyphenols and amino acids, ester catechins, non-ester catechins and caffeine in YT-CM and GT-CM was significantly higher than that of BT-CM. The in vitro antioxidant capacity of YT-CM and GT-CM was also significantly stronger than that of BT-CM. Three T-CMs had the effects of inhibiting proliferation, arresting cell cycle and inducing apoptosis in HepG2 and Bel7402 cells, especially YT-CM and GT-CM. Western blot analysis showed three T-CMs activated PI3K/AKT/mTOR signaling pathway and regulated the expression levels of apoptosis-related proteins Bax, Bcl-2 and Caspase-3/9. YT-CM and GT-CM had better ability to change the signal pathway than BT-CM.

Conclusion

In short, T-CMs, which combined different degrees of fermentation tea with C. maxima, were rich in nutrients and biologically active substances. T-CMs, especially YT-CM and GT-CM, are healthy drinks that help to prevent and treat liver cancer.

Effect of In Vitro Gastrointestinal Digestion on Amino Acids, Polyphenols and Antioxidant Capacity of Tamarillo Yoghurts

Laird’s Large tamarillo powder is high in protein (10%) essential amino acids (EAAs), gamma-aminobutyric acid (GABA) and polyphenols (0.6% phenolics plus anthocyanins) and fibre 25%. This study aimed to investigate, using a standardized static in vitro digestion model, the stability of amino acids and antioxidant capacity of polyphenols in yoghurt fortified with 5, 10 and 15% tamarillo powder either before (PRE) or after (POS) fermentation. Compared to plain yoghurt, the fruit polyphenols (rutinosides and glycosides) were retained and substantial increases in FEAAs (free essential amino acids), total phenolic content (TPC) and antioxidant activity were observed particularly at the end of intestinal phase of digestion. Together with SDS-PAGE results, peptides and proteins in tamarillo yoghurts were more easily digested and therefore may be better absorbed in the small intestine compared to the control. TPC and antioxidant activity of fortified yoghurts increased significantly after in vitro digestion. Relatively high bioaccessibilty of chlorogenic acid and kaempferol-3-rutinoside in digested PRE samples was observed. The results suggest that the yoghurt matrix might protect some compounds from degradation, increasing bioaccessibility and in the small intestine allow increased absorption and utilization possible. Fortification would deliver intact polyphenols and fibre to the large intestine and improve gut health. Further research of acceptability, shelf life, and then trials for health effects should be implemented.

The Sensory Quality and the Physical Properties of Functional Green Tea-Infused Yoghurt with Inulin

The purpose of this study was to investigate the influence of the addition of inulin (3%, 6% and 9%) to green tea-infused set type yoghurt on its sensory quality and physical properties. Yogurts were made by combining green tea with milk and inulin and inoculated with freeze-dried starter cultures YO-122. Incubation was conducted at 43 °C for approximately 4.5 h until a pH value of 4.5–4.6 was achieved. For the prepared yoghurts, a panel of experts (n = 10) was selected, characterized 35 attributes and conducted a sensory quality assessment of these yoghurts using the Quantitative Descriptive Profile method. Additionally, instrumental analyses such as yield stress, adhesiveness, firmness, physical stability and color parameters were also carried out. The use of green tea infusion increased the perception of green tea flavor, bitterness, astringency, dark color of the yoghurt and the existing whey, which worsened the overall sensory quality of the yoghurt. The addition of inulin (9%) to the green tea yoghurt, increased the perception of sweet, peach flavor and aroma and improved the firmness of the yoghurt while reducing the perception of sour taste, which improved the sensory quality of the yoghurt. Both inulin and green tea affected the physical properties of the yoghurts, causing an increase in the yield stress (43%, and 20%, respectively) and deteriorated the stability of the yoghurts. Green tea affected the color of the yoghurts, causing the lightness to decrease. The L* parameter decreased from 89.80 for the control sample to 84.42 for the green tea infused yoghurt. The use of infused green tea in yoghurt production makes it necessary to use ingredients that will neutralize its adverse effects on sensory quality and physical parameters of yoghurt, and such an additive can be prebiotic fiber–inulin at a concentration of 9%.

Fuzhuan brick tea supplemented with areca nuts: Effects on serum and gut microbiota in mice

Areca nut and Fuzhuan brick tea, a type of natural plant products, have obvious effects of fat reduction and weight loss; however, there is no report on their synergistic effect. This study investigated the effects of Fuzhuan brick tea supplemented with different concentrations of areca nut (5% (LAF), 10% (MAF), and 20% (HAF)) on serum and gut microbiota in Kunming (KM) mice. The results showed that Fuzhuan brick tea supplemented with areca nuts (AFTs) could reduce weight, prevent the accumulation of fat, inhibit the increase in the levels of serum triglyceride, total cholesterol, low-density lipoprotein cholesterol, blood glucose, free fatty acid, insulin, and total bile acid, alleviate the decrease in high-density lipoprotein cholesterol level, and regulate the composition of gut microbiota by high-fat diet intervention. The HAF group with 20% areca nut content showed the best effect. These results could provide a novel approach to prevent obesity and hyperlipidemia. PRACTICAL APPLICATIONS: Consumption of areca nut and tea is widespread in Asia and other regions. As a controversial raw material, the damage due to areca nut to oral mucosa health has often aroused public concern and heated discussion; however, its medicinal value has been confirmed in terms of its pharmacological effects in various aspects. Fuzhuan brick tea, a type of traditional postfermented dark tea, has been confirmed to exert effects of antiobesity. Therefore, the areca nut and Fuzhuan brick tea, as a type of natural plant products, have obvious effects of fat reduction and weight loss; however, their synergistic effect has not been reported. To our knowledge, this study is the first to explore the effects of the Fuzhuan brick tea supplemented with areca nuts (AFTs) on serum and gut microbiota in mice. On the premise of exerting their beneficial effects (especially in terms of easing food stagnation and eliminating indigestion) and reducing their toxic and side effects, the effects of AFTs on health were further clarified, which could provide a novel direction for the development and utilization of areca nut. Moreover, our research would increase public understanding of areca nut and provide guidance to the Fuzhuan brick tea processing industry.

Effects of using different O2 scavengers on the qualitative attributes of bifidus yogurt during refrigerated storage

Among the factors that adversely influence the viability of probiotics, the oxygen content of the product and the permeation of oxygen molecules through the packaging system have a noticeable role in the viability loss during the manufacture and storage of fermented milk products. The objective of this study was to examine the qualitative attributes of probiotic yogurt containing different O₂ scavengers, including the commercial O₂ absorber and cysteine-ascorbic acid. Bifidobacterium lactis BIA-7 and B. longum BIA-8 were used as probiotic strains for the production of bio-yogurts. The biochemical parameters, including the changes in pH, titratable acidity, redox potential and incubation time, were determined throughout the fermentation period at 30-min intervals. Also, the changes in viable count, pH, redox potential, titratable acidity, and dissolved oxygen were evaluated at 7-day intervals during the 28 days of refrigerated storage. In addition, the evaluation of rheological and sensory properties measured in the freshly made samples was carried out. The results showed that the utilization of different oxygen scavengers has an effective impact on the decrement of oxygen content and improvement of probiotic viability. As such, the population of B. lactis in the treatments containing various oxygen scavengers was maintained above 7 log CFU/mL throughout the refrigerated storage. Notwithstanding the effective function of cysteine-ascorbic acid in the enhancement of viability, the containing treatments had not only weaker gel structure probably due to short incubation time (360 min) and fast acidification [22.20-22.35 (˚D/min) × 10^-2], but also lower sensory acceptance. Overall, the yogurt treatment containing commercial O₂ scavenger and B. lactis indicated a great potential for the industrial applications. To the best of our knowledge, there is no study on the efficiency of commercial O₂ absorber as a potential factor to maintain the viability of probiotics in yogurt.

Effect of Sea Buckthorn (Hippophae rhamnoides L.) Mousse on Properties of Probiotic Yoghurt

The stability of the physico-chemical and sensory characteristics of yoghurts during refrigerated storage is important for industry and the consumer. The aim of the study was to evaluate the nutritional value, microbiological quality, sensory properties, and structure of natural probiotic yoghurts made with the addition of sea buckthorn fruit mousse during refrigerated storage. In this study, we produced natural, probiotic organic yoghurts with the addition of superfoods, i.e., sea buckthorn (Hippophae rhamnoides L.) fruit mousse, using ABT-1 probiotic yoghurt starter culture based on Lactobacillus acidophilus LA-5, Bifidobacterium lactis BB-12, and Streptococcus thermophilus. Physico-chemical (acidity, nutritional value, and structure) as well as microbiological and sensory changes occurring during 21-day refrigerated storage were determined. The yoghurts were characterized by high sanitary and hygienic quality during the whole refrigerated storage. Fourier-Transform Infrared (FTIR) spectra were also used in the analyses of the obtained yoghurt samples. The applied yoghurt additive was visible at the spectral level as an increase in the intensity of the characteristic bands for vibrations related to protein, fat, and polysaccharide structures. Sea buckthorn can be used as a modern and unconventional addition to yoghurts with health-promoting properties. Micrographic studies have shown that the addition of sea buckthorn mousse significantly changes the microstructure of the yoghurt. The structure of sea buckthorn to yoghurt seems to be more susceptible to the influence of damaging factors, which is also confirmed by the FTIR test conducted during the storage.

Effect of Black Tea Infusion on Physicochemical Properties, Antioxidant Capacity and Microstructure of Acidified Dairy Gel during Cold Storage

The impacts of black tea infusion on physicochemical properties, antioxidant capacity and microstructure of stirred acidified dairy gel (ADG) system have not been fully explored. These impacts were studied during a 28-day cold storage (4 °C) period to explore the feasibility and technical boundaries of making acidified dairy gels in which black tea infusion (BTI) is incorporated. Reconstituted skim milks containing different proportions of BTI were acidified by GDL (glucono-δ-lactone) at 35 °C for making ADG systems. Both textural properties and structural features were characterized; antioxidant capacity was determined through three assays. They are (1) free radical scavenging ability by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; (2) ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)] assay and (3) ferric reducing antioxidant power (FRAP) assay. The microstructure of the ADGs was observed using SEM (scanning electron microscopy) and CLSM (confocal laser scanning microscopy). Results showed that BTI significantly increased the antioxidant capacity of the gel systems and the gel containing 15% BTI was as stable as the control gel in terms of syneresis rate. However lower phase stability (higher syneresis rate) was observed in the ADG with a higher portion of BTI (30% to 60%). The microstructure of the ADGs observed may explain to the phase stability and textural attributes. The results suggested that tea polyphenols (TPs) improved antioxidant capacity in all samples and the interactions between BTI and dairy components significantly altered the texture of ADGs. Such alterations were more pronounced in the samples with higher proportion of BTI (60%) and/or longer storage time (28 days).

Co-Supplementation of Flos Sophorae Extract with Tremella fuciformis Polysaccharides Improves Physicochemical, Textural, Rheological, and Antioxidant Properties of Low-Fat Yogurts

Flos Sophorae extract (FSE) with abundant rutin and Tremella fuciformis polysaccharides (TP) could act as novel natural improvers of low-fat yogurt due to their health benefits and properties of interacting with proteins. This study attempted to understand how FSE or its combination with TP influences physicochemical, textural, and antioxidant properties of low-fat yogurts. The results indicated that the low concentrations of FSE (1.2 or 2.4%) increased the antioxidant activity, prompted the S. thermophilus growth, water holding capacity (WHC), and textural and sensory properties, and shortened the fermentation time, but reduced the rheological properties of yogurts compared with the control. Co-supplementing appropriate TP with the optimum FSE concentration (2.4%) improved the rheological properties, and further enhanced the S. thermophilus growth, WHC, textural and antioxidant properties, and sensory scores of yogurts compared with the 2.4% FSE group, with the best effects at 0.4 mg/mL TP. Taken together, co-supplementation of polyphenols extract FSE with Tremella fuciformis polysaccharides may be an available strategy to optimize health-promoting properties and overcome defects of low-fat yogurts.

Probiotic Yogurt with Brazilian Red Propolis: Physicochemical and Bioactive Properties, Stability, and Shelf Life

This study aimed to evaluate the quality parameters in probiotic yogurt produced with Brazilian red propolis to replace potassium sorbate used in conventional yogurt (CY). Microbiological stability and shelf life, physicochemical properties (pH, acidity, chemical composition, and fatty acids), and bioactive properties (phenolic compounds and antioxidant activity) were evaluated. The addition of red propolis (0.05%) to replace the potassium sorbate did not change the pH, acidity, fatty acid profile, chemical composition, or shelf life. Microbiological stability of at least 28 days was achieved, while a drastic reduction in the lactic acid bacteria content was observed in the CY during refrigeration storage. Phenolic total contents were higher than those of the control, and consequently, yogurt with red propolis showed higher antioxidant activity. PRACTICAL APPLICATION: The study indicates that Brazilian red propolis at 0.05% concentration to replace the potassium sorbate is an efficient alternative for use in yogurt production. The knowledge acquired about these types of Brazilian propolis provides an important contribution to food research in the discovery of new functional products to the market, seeking a healthier diet. Therefore, the produced yogurt proves to be an innovative product with functional and probiotic potential to be placed on the market.

Potential application of herbs and spices and their effects in functional dairy products

Herbs and spices come from different parts of the plant are used to impart an aroma and taste to food. Several herbs have therapeutic properties such as antioxidative, anti-inflammatory, antidiabetic, antihypertensive and antimicrobial activities. Therefore, fortification of dairy foods with herbs and spices could help to provide functional dairy products with nutritional and medicinal values. Also, herbs and spices are used to improve the appearance and attractiveness of fortified foods for consumers and to increase the sale of those herbs. Therefore, only the highest quality herbs or spices can be added to dairy products to combat contaminating microorganisms. In this review the latest progresses in the dairy sector concerning the addition of numerous herbs and spices in different forms (i.e. powder, fresh, extract, essential oils) to dairy food has been conversed. Also, the effects of those herbs and spices on the quality of dairy products such as yoghurts, cheeses, butter, gee and ice creams have been presented.

New Acylglycosides Flavones from Fuzhuan Brick Tea and Simulation Analysis of Their Bioactive Effects

Four novel acylglycosides flavones (AGFs) including two quercetin acylglycosides and two kaempferol acylglycosides were isolated from Fuzhuan brick tea (FBT) as follows: quercetin 3-O-[α-l-rhamnopyranosyl (1→3)] [2-O’’-(E)-p-coumaroyl] [β-d-glucopyranosyl (1→3)-α-l-rhamnopyranosyl (1→6)]-β-d-galactoside was named as camelliquercetiside E (1), quercetin 3-O-[α-l-rhamnopyranosyl (1→3)] [2-O’’-(E)-p-coumaroyl] [α-l-rhamnopyranosyl (1→6)]-β-d-galactoside was named as camelliquercetiside F (2), kaempferol 3-O-[α-l-arabinopyranosyl (1→3)] [2-O’’-(E)-p-coumaroyl] [β-d-glucopyranosyl (1→3)-α-l-rhamnopyranosyl (1→6)]-β-d-glucoside was named as camellikaempferoside D (3), kaempferol 3-O-[α-l-arabinopyranosyl (1→3)] [2-O’’-(E)-p-coumaroyl] [α-l-rhamnopyranosyl (1→6)]-β-d-glucoside was named as camellikaempferoside E (4). Chemical structures of AGFs were identified by time-of-flight mass (TOF-MS) and NMR spectrometers (¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMBC and HSQC), and the MS² fragmentation pathway of AGFs was further investigated. The inhibitory abilities of AGFs and their proposed metabolites on α-glucosidase and HMG-CoA reductase were analyzed by molecular docking simulation, and the results suggested that inhibitory activities of AGFs were significantly affected by acyl structure, number of glycosyl and conformation, and part of them had strong inhibitory activities on α-glucosidase and HMG-CoA reductase, suggesting that AGFs and their metabolites might be important ingredients that participate in the regulation of hypoglycemic and hypolipidemic effects. The results provided new AGFs and research directions for the practical study of FBT health functions in future.