An integrated strategy between food chemistry, biology, nutrition, pharmacology, and statistics in the development of functional foods: A proposal

Chemistry and Biological Activities of Processed Camellia sinensis Teas: A Comprehensive Review

Tea is a typical processed beverage from the fresh leaves of Camellia sinensis [Camellia sinensis (L.) O. Kuntze] or Camellia assamica [Camellia sinensis var. assamica (Mast.) Kitamura] through different manufacturing techniques. The secondary metabolites of fresh tea leaves are mainly flavan-3-ols, phenolic acids, purine alkaloids, condensed tannins, hydrolysable tannins, saponins, flavonols, and their glycoside forms. During the processing, tea leaves go through several steps, such as withering, rolling, fermentation, postfermentation, and roasting (drying) to produce different types of tea. After processing, theaflavins, thearubigins, and flavan-3-ols derivatives emerge as the newly formed compounds with a corresponding decrease in concentrations of catechins. Each type of tea has its own critical process and presents unique chemical composition and flavor. The components among different teas also cause significant changes in their biological activities both in vitro and in vivo. In the present review, the progress of tea chemistry and the effects of individual unit operation on components were comprehensively described. The health benefits of tea were also reviewed based on the human epidemiological and clinical studies. Although there have been multiple studies about the tea chemistry and biological activities, most of existing results are related to tea polyphenols, especially (-)-epigallocatechin gallate. Other compounds, including the novel compounds, as well as isomers of amino acids and catechins, have not been explored in depth.

Phenethyl isothiocyanate stimulates glucose uptake through the Akt pathway in C2C12 myotubes

Phenethyl isothiocyanate (PEITC) is an aromatic isothiocyanate present in cruciferous vegetables. Several studies have shown that isothiocyanates regulate various intracellular signaling pathways, and thereby show anti-inflammatory and detoxifying activities. However, little is known about the effects of PEITC on glucose metabolism. In this study, we examined whether PEITC promotes glucose utilization in mouse skeletal muscle cells, C2C12 myotubes. PEITC induced glucose uptake, glucose transporter 4 (Glut4) translocation to the plasma membrane, and activation of Akt and ERK in C2C12 cells. Inhibition of Akt suppressed PEITC-induced Glut4 translocation and glucose uptake, whereas ERK inhibition did not. Furthermore, PEITC increased phosphorylation of ErbB2 and ErbB3. Treatment with a pan-ErbB inhibitor reduced Akt activation and the subsequent glucose uptake induced by PEITC. These results indicate that PEITC promotes glucose utilization through the ErbB/Akt pathway in C2C12 myotubes. PEITC may therefore serve as a dietary constituent with beneficial effects on the carbohydrate metabolism.

Abbreviations: PEITC: phenethyl isothiocyanate; Glut4: glucose transporter 4; PI3K: phosphatidylinositide 3-kinase; Nrf2: erythroid−2-related factor; ARE: antioxidant response element; HO−1: heme oxygenase−1; NRG: neuregulin

Advances in renewable plant-derived protein source: The structure, physicochemical properties affected by ultrasonication

In recent years, there has been increasing interest in renewable and sustainable protein resource of plant origin. The reasons for this are summarized as follows: (1) green, low-cost, environmental friendly and sustainable concepts are deeply rooted in people's minds; (2) long-term use of animal protein can lead to high blood pressure, obesity, negative environmental impacts; (3) more and more vegetarians are emerged; (4) many consumers still do not accept food grade insect. Based on this situation, this paper links eco-innovative ultrasound technology to plant-derived sustainable proteins resource, and magnifies the advantages of both at the same time. Ultrasound is a novel, green and rapid developing environmental friendly technology, which is suitable for up scaling and improving the physicochemical properties of protein. This review summarizes the mechanisms, cavitation properties of ultrasonic field, consumption of energy, applications of spectroscopic techniques for evaluating plant-derived proteins conformation changes, effects of ultrasound on the structure and physicochemical properties of plant-derived renewable proteins, and application of ultrasound treatment proteins in food industry. Furthermore, future research to better utilize this green technology is suggested. In this way, it not only conforms to the concept of sustainable, high-efficiency, and environmental protection of the food protein industry, but also clarifies the relationship between protein structure and properties, which are conducive to the application of ultrasound in protein industrialization.

Antioxidant Properties of a Yogurt Beverage Enriched with Salal (Gaultheria shallon) Berries and Blackcurrant (Ribes nigrum) Pomace during Cold Storage

Aqueous extracts (20% w/w) of dried berry fruits and skins were used as sources of phenolic compounds to fortify yogurt beverages. The total phenol and anthocyanin content of the reformulated yogurts were determined, and the antioxidant properties were compared to plain yogurt (C) during storage at 4 °C for a total period of four weeks. Yogurt beverages fortified with salal berry (SB) extracts contained higher amounts of phenolic compounds (>69.9 μg GAE/mL) and anthocyanins (>19.12 mg C3G/L) compared to drinks supplemented with blackcurrant pomace (BC) extract (>50.13 μg GAE/mL and >10.80 mg C3G/L respectively). Storage affected the stability of anthocyanins, whereas total phenol content remained unaffected. Yogurts with SB displayed the highest antioxidant capacity followed by samples with BC, which is attributed to the radical scavenging effect of the bioactive compounds present with antioxidant properties. The antioxidant capacity of the yogurt beverages fortified with fruit extracts was maintained during cold storage. Findings of this study indicate that SB and BC pomace can be used as functional ingredients to increase the antioxidant potential of yogurt beverages.

Composition and Characteristics of Yam Juice Fermented by Lactobacillus plantarum and Streptococcus thermophilus

In this study, Lactobacillus plantarum (LP), alone or in combination with Streptococcus thermophilus, was used to ferment yam juice. Changes in the composition (phenols, organic acids, reducing sugars and volatile substances) and functional characteristics (antioxidative activity and ability to regulate the intestinal flora) of yam juice during fermentation were investigated. The results showed that the total phenolic (TP) content increased from 201.27 to 281.27 and 285.77 μg/mL for LP- and L. plantarum and S. thermophilus (LPST)-fermented yam juice, respectively. The antioxidative activity of yam juice improved significantly after fermentation, highly correlating with its TP content. In addition, LP- or LPST-fermented yam juice had positive effects on members of the human intestinal flora, improving the activity of Bifidobacterium and inhibiting the growth of Escherichia coli. Sensory analysis showed that LPST-fermented yam juice had a highest score. The results of this study showed that fermented yam juice can serve as a healthy beverage for consumers with low immunity or an imbalance of the intestinal flora.

Evaluating the impact of supercritical-CO2 pressure on the recovery and quality of oil from "horchata" by-products: Fatty acid profile, α-tocopherol, phenolic compounds, and lipid oxidation parameters

The effect of supercritical carbon dioxide (SC-CO₂) (10-40 MPa) and conventional extraction (CE) to recover oil from by-products obtained during "horchata" production was assessed. To evaluate both extraction techniques, the fatty acid composition, polyphenols, α-tocopherol, antioxidant capacity and lipid oxidation parameters of the extracts obtained were analysed. A linear relationship between extraction pressure and oil yield was observed. However, the highest oil yield was obtained under conventional extraction. The by-products from "horchata" presented a profile where monounsaturated fatty acids (MUFA) were the predominant, representing ≈ 70% of total fatty acids. The amount of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) was higher and MUFA lower at 10 MPa samples compared to the oils extracted using SC-CO₂ at 20, 30 or 40 MPa, where no differences were detected. The content of α-tocopherol was significantly higher after SC-CO₂ treatments compared to conventional extraction, independently of the applied treatment. On the other hand, the values of phenolic compounds and total antioxidant activity (TAC) increased as the pressure conditions of the SC-CO₂ extraction increased, presenting a linear adjustment of the data. Regarding lipid oxidation, the lower oxidation indexes were obtained when the SC-CO₂ pressure increased. Finally, our results confirmed that the application of SC-CO₂ could be a potential alternative to conventional extraction in order to obtain oils from "horchata" by-products rich in high-added value compounds without the use of organic solvents which can be toxic.

Comparative Evaluation of the Antioxidant Capacities and Organic Acid and Volatile Contents of Mango Slurries Fermented with Six Different Probiotic Microorganisms

Mango slurries were fermented with 6 different probiotic microorganisms (Lactobacillus plantarum, Streptococcus thermophilus, Lactobacillus casei, Saccharomyces cerevisiae D254, S. cerevisiae DV10, and S. cerevisiae R2) to develop products with higher bioactivity. Changes in pH, reducing sugars, organic acids, and volatile compounds were determined. In addition, total phenolics and antioxidant capacity during fermentation were monitored. Among the strains used, S. cerevisiae D254 exhibited the fastest utilization of sugar in a mango slurry. Different volatile compounds were produced, mainly consisting of fatty acids, alcohols, and esters. S. cerevisiae DV10 produced higher amounts of esters and alcohols. The antioxidant capacity of the mango slurries improved by different degrees after fermentation with the six probiotic microorganisms. Fermentation with L. plantarum obtained the most organic acids as well as total phenolics and exhibited the highest FRAP and CUPRAC values. The results of this study indicated that fermentation with probiotic microorganisms can enhance the health benefits obtained from mango slurries. PRACTICAL APPLICATION: Probiotic-fermented mango slurry is a fermentation product that combines the nutritional value of mango with the health benefits of probiotics. Probiotic fermentation improves the flavor of a mango slurry and increases the availability and variety of mango products that can be appreciated by consumers.

Physicochemical, thermal, and rheological properties of nixtamalized blue-corn flours and masas added with huitlacoche (Ustilago maydis) paste

The aim of this work was to evaluate the effect of the addition of huitlacoche paste to nixtamalized blue-corn flours (NBCF) on the physicochemical, thermal, and rheological properties of masas. Raw blue maize was nixtamalized (hydrothermal alkalinized process), then was wet-milled in a stone mill, masa was dehydrated, pulverized and sieved to obtain NBCF; commercial nixtamalized blue-corn flour (CNBCF) was used as a control. Huitlacoche paste in concentrations of 3, 6, 9, 12, 15, and 18% was added to nixtamalized flours. Characteristics of the blue grain showed its great effects on water absorption, viscosity, and masa cohesiveness; the addition of huitlacoche significantly influenced adhesiveness, water-absorption, color, and the rheological properties (p < 0.05). Values between 0.03 and 0.083 kg-force resulted in masas with optimal adhesiveness. The inclusion of huitlacoche paste can be achieved with a maximal addition of 9% in NBCF for an industrial process and could comprise a new industrialization alternative.

Hepatoprotective and Antioxidant Activities of Oil from Baru Almonds (Dipteryx alata Vog.) in a Preclinical Model of Lipotoxicity and Dyslipidemia

The oil obtained from baru (Dipteryx alata Vog.) almonds exhibits high energy value and is reported in popular medicine for the treatment of rheumatic diseases and reproductive disturbances. Although baru oil is used in domestic cuisine, the chemical characterization of this oil and its effects on lipid metabolism are still poorly understood. Therefore, this study evaluated the fatty acid (FA) profile and the effects of baru oil on liver and aorta in a murine model of dyslipidemia. The chromatographic profile of baru oil showed high levels of unsaturated FAs, especially oleic acid. Saturated FAs, such as palmitic and lignoceric acids, were found in lower amounts. Hypercholesterolemia was induced in male Wistar rats by daily administration of a lipid emulsion by gavage for 15 weeks. Biochemical and histopathological analysis were performed on serum, aorta, and liver. The results demonstrated that animals developed marked hypercholesterolemia, liver steatosis, and increased lipid peroxidation in the aorta. Treatment with baru oil attenuated lipid peroxidation and drastically reduced liver damage, especially ballooning degeneration and steatosis. By restricting vascular and hepatic injury, this oil showed potential applicability as a functional food, reinforcing its use in popular medicine and domestic cuisine.

Shelf life study of healthy pork liver pâté with added seaweed extracts from Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata

The effect of the addition of seaweed extracts from three brown algae species [Ascophyllum nodosum (AN), Fucus vesiculosus (FV) and Bifurcaria bifurcata (BB)], which are a great source of natural antioxidants, on the oxidative stability of refrigerated low-fat pork liver pâtés was studied. In the studied pâtés, half of pork fat was replaced with a mixture consisting of canola and high-oleic sunflower oil (75:25, v/v), thus improving their fatty acid profile in terms of polyunsaturated fatty acids (PUFA). In order to avoid the oxidation of PUFA in the new samples, seaweed extracts (500 ppm) were added. In addition, some samples were formulated with a synthetic antioxidant (BHT at 50 ppm) (BHT) and a control batch (CON) (without antioxidant) was also prepared, for comparison purposes. Thus, in total, five batches of liver pâté were prepared: CON, BHT, AN, FV and BB. Pâté samples were analyzed at 0, 45, 90, 135 and 180 days of refrigerated storage at 4 °C. The addition of seaweed extracts did not modify significantly (P > 0.05) the chemical composition or microbial characteristics of healthy pork liver pâté, except for the protein content, which resulted in a significant increase (≈2-3%) in the batches manufactured with addition of seaweed extracts compared to control samples. At the end of storage (180 days), L* values were significantly lower in the FV and BB batches than in the other batches. Moreover, the a* and b* values were also significantly lower in CON batches than in the samples with antioxidants added. Differences in oxidative parameters (conjugated dienes, TBARs and carbonyls) among batches were observed at the end of the storage time, showing samples with seaweed extracts a similar degree of protection against oxidation compared to BHT formulated samples. A decline of the volatile compounds was noted in all the batches during storage. The total volatile compounds at the end of the storage were significantly lower in BTH, AN, or BB batches than in control batches.

Novel Food Processing and Extraction Technologies of High-Added Value Compounds from Plant Materials

Some functional foods contain biologically active compounds (BAC) that can be derived from various biological sources (fruits, vegetables, medicinal plants, wastes, and by-products). Global food markets demand foods from plant materials that are “safe”, “fresh”, “natural”, and with “nutritional value” while processed in sustainable ways. Functional foods commonly incorporate some plant extract(s) rich with BACs produced by conventional extraction. This approach implies negative thermal influences on extraction yield and quality with a large expenditure of organic solvents and energy. On the other hand, sustainable extractions, such as microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), high-pressure assisted extraction (HPAE), high voltage electric discharges assisted extraction (HVED), pulsed electric fields assisted extraction (PEF), supercritical fluids extraction (SFE), and others are aligned with the “green” concepts and able to provide raw materials on industrial scale with optimal expenditure of energy and chemicals. This review provides an overview of relevant innovative food processing and extraction technologies applied to various plant matrices as raw materials for functional foods production.

Effect of αS1-casein genotype on phenolic compounds and antioxidant activity in goat milk yogurt fortified with Rhus coriaria leaf powder

The aim of this work was to evaluate the phenolic compounds and antioxidant activity of goat milk yogurt characterized by different α_S1-casein genotypes and fortified with Rhus coriaria leaf powder. The α_S1-casein genotype was determined by isoelectric focusing, total phenol content was determined by the Folin-Ciocalteu method, phenolic compounds were identified and quantified by HPLC-UV analysis, and antioxidant activity was measured using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power. The statistical analysis showed a significant effect of the studied factors. Comparing different genotypes it emerged that yogurt from goats with weak alleles at CSN1S1 loci (FF) showed the lowest phenolic compounds and therefore a lower antioxidant activity compared with yogurt from goats with strong alleles at CSN1S1 loci (AA, BB, AB). Rhus coriaria-fortified yogurt showed a significant increase in total phenolic compounds and antioxidant activity in comparison with plain yogurt. The FF-fortified yogurt presented the lowest total phenol content and antioxidant activity. This could be due to a greater capacity of proteins and peptides in this yogurt to form stable complexes with phenols. The different total phenol content detected in R. coriaria-fortified yogurt indicates that the α_S1-casein genotype influenced the amount of added phenols that are bound to the caseins and, therefore, the part that remains free and that affects the biological capacity of the final product.

Bioinactivation FE: A free web application for modelling isothermal and dynamic microbial inactivation

Mathematical models developed in predictive microbiology are nowadays an essential tool for food scientists and researchers. However, advanced knowledge of scientific programming and mathematical modelling are often required in order to use them, especially in cases of modelling of dynamic and/or non-linear processes. This may be an obstacle for food scientists without such skills. Scientific software can help making these tools more accessible for scientists lacking a deep mathematical or computing background. Recently, the R package bioinactivation was published, including functions (model fitting and predictions) for modelling microbial inactivation under isothermal or dynamic conditions. It was uploaded to the Comprehensive R Archive Network (CRAN), but users need basic R programming knowledge in order to use it. Therefore, it was accompanied by Bioinactivation SE, a user-friendly web application including selected functions in the software for users without a programming background. In this work, a new web application, Bioinactivation FE, is presented. It is an extension of Bioinactivation SE which includes an interface to every function in the bioinactivation package: model fitting of isothermal and non-isothermal experiments, and generation of survivor curves and prediction intervals. Moreover, it includes several improvements in the user interface based on the users' feedback. The capabilities of the software are demonstrated through two case studies using data published in the scientific literature. In the first case study, the response of Escherichia coli to isothermal and non-isothermal treatments is compared, illustrating the presence of an induced thermal resistance. In the second, the effect of nanoemulsified d-limonene on the thermal resistance of Salmonella Senftenberg is quantified.

Extraction of bioactive compounds and essential oils from mediterranean herbs by conventional and green innovative techniques: A review

Market interest in aromatic plants from the Mediterranean is continuously growing mainly due to their medicinal and bioactive compounds (BACs) with other valuable constituents from essential oils (EOs). From ancient times, these plants have been important condiments for traditional Mediterranean cuisine and remedies in folk medicine. Nowadays, they are considered as important factors for food quality and safety, due to prevention of various deteriorative factors like oxidations and microbial spoilage. EOs have different therapeutic benefits (e.g. antioxidant, anti-inflammatory, antimicrobial, and antifungal), while BACs mostly affect nutritive, chemical, microbiological, and sensory quality of foods. Currently, many plant extracts are used for functional (healthy) foods, which additionally fuels consumer and industrial interest in sustainable and non-toxic routes for their production. EO yields from dried plants are below 5%. Their extraction is strongly dependent on the hydrophobic or lipophilic character of target molecules, hence the common use of organic solvents. Similarly, BACs encompass a wide range of substances with varying structures as reflected by their different physical/chemical qualities. Thus, there is a need to identify optimal non-toxic extraction method(s) for isolation/separation of EO/BCs from plants. Various innovative non-thermal extractions (e.g. ultrasound-, high-pressure-, pulsed electric fields assisted extraction, etc.) have been proposed to overcome the above mentioned limitations. These techniques are "green" in concept, as they are shorter, avoid toxic chemicals, and are able to improve extract yields and quality with reduced consumption of energy and solvents. This research provides an overview of such extractions of both BAC and EOs from Mediterranean herbs, sustained by innovative and non-conventional energy sources.

Effect of pre-treatments on the antioxidant potential of phenolic extracts from barley malt rootlets

In this study, barley malt rootlets (BMR) were subjected to five different pre-treatments (steaming (220 °C), roasting (60 °C), autoclaving (121 °C), microwaving (160-800 W, 30-120 s) and enzyme treatment). Total phenolic content (TPC) and antioxidant activity of the BMR extracts were evaluated for both free and bound phenolics. The free phenolic content for non-treated extract was 1.8 mg/g of dry weight of BMR with 17.5% of antioxidant activity. Among the pre-treatments, autoclaving exhibited the highest values for free phenolics of 3.8 mg/g of dry weight of BMR and 71.6% of antioxidant activity. Pre-treatments did not show any effect on bound phenolic content, but increased antioxidant activity. The highest %DPPH activity for bound phenolics was observed for microwave treatment (160 W, 120 s) with 49.9%. Overall, pre-treatments significantly increased the free phenolic content of BMR phenolic extracts. Additional research is necessary to understand the phenolic profile and the thermal interactions of bound phenolic extracts.

Berries extracts as natural antioxidants in meat products: A review

The aim was to evaluate antioxidants from berries as replacement food additives for inhibition of lipid and protein oxidation in meat and meat products, since meats are highly susceptible to oxidation. Oxidation can be delayed/retarded by synthetic antioxidants with phenolic structures (e.g. butylated hydroxytoluene). However, new natural alternatives are needed for synthetic antioxidants due to the controversy regarding their possible negative health effects and consumers' demand for more 'natural' food additives. Berries are a good source of phenolic compounds, especially anthocyanins, which can be used as the potential alternative. Reviewed berries included bearberry (Arctostaphylos sp.), blueberry (Vaccinium sp.), blackberry (Rubus sp.), blackcurrant (Ribes nigrum), cranberry (Vaccinium sp.), cloudberry (Rubus chamaemorus), strawberry (Fragaria ananassa), and grape berries (Vitis sp.). Data implied that blueberries, blackberries, cranberries, and grapes can be useful for replacing/decreasing synthetic antioxidants in meat products. Their extracts have antioxidant polyphenols with health benefits that are useful for stabilizing meat products.