Recovery of Bioactive Compounds from Unripe Red Grapes (cv. Sangiovese) through a Green Extraction

The multiple actions of grape and its polyphenols on female reproductive processes with an emphasis on cell signalling

Grapes are an economically important fruit crop, and their polyphenols (mainly phenolic acids, flavanols, flavonols, anthocyanins, proanthocyanidins, and stilbenes) can exert a wide range of health benefits as an interesting and valuable dietary supplement for natural complementary therapy. However, their potential physiological and therapeutic actions on reproductive processes have not been sufficiently elucidated. This evidence-based study presents current knowledge of grape extracts and polyphenols, as well as their properties and therapeutical actions in relation to female reproduction in a nutshell. Grape extract, and its polyphenols such as resveratrol, proanthocyanidin B2 or delphinidin may influence female reproductive physiology and pathology, as well as regulate multiple signaling pathways related to reproductive hormones, steroid hormones receptors, intracellular regulators of oxidative stress and subsequent inflammation, apoptosis, and proliferation. Their role in the management of ovarian cancer, age-related reproductive insufficiency, ovarian ischemia, PCOS, or menopausal syndrome has been indicated. In particular, the potential involvement of grapeseed extracts and/or proanthocyanidin B2 and delphinidin on ovarian steroidogenesis, oocyte maturation, and developmental capacity has been implicated, albeit at different regulatory levels. Grape polyphenols exert a wide range of health benefits posing grape extract as an interesting and valuable dietary supplement for natural complementary therapy. This evidence-based study focuses on the actions of grapeseed extract and grape polyphenols on female reproductive processes at various regulatory levels and multiple signalling pathways by regulating reproductive hormones (GnRH, gonadotropins, prolactin, steroid hormones, IGFBP), steroid receptors, markers of proliferation and apoptosis. However, lack of knowledge of standardized dosages so far limits their clinical application despite the wide range of their biological and therapeutic potentials.

Screening and Characterization of Phenolic Compounds from Selected Unripe Fruits and Their Antioxidant Potential

The food sector's interest in sustainability and the demand for novel bioactive compounds are increasing. Many fruits are wasted every year before ripening due to various climatic conditions and harsh weather. Unripe mangoes, grapes, and black lemons could be rich sources of phenolic compounds that need to be fully elucidated. Using fruit waste as a source of bioactive chemicals has grown increasingly appealing as it may have significant economic benefits. Polyphenols are beneficial for human health to inhibit or minimize oxidative stress and can be used to develop functional and nutraceutical food products. In this context, this study aimed to characterize and screen unripe mangoes, grapes, and black lemons for phenolic compounds using LC-ESI-QTOF-MS/MS and their antioxidant activities. Unripe mangoes were quantified with higher total phenolic content (TPC, 58.01 ± 6.37 mg GAE/g) compared to black lemon (23.08 ± 2.28 mg GAE/g) and unripe grapes (19.42 ± 1.16 mg GAE/g). Furthermore, unripe mangoes were also measured with higher antioxidant potential than unripe grapes and black lemons. A total of 85 phenolic compounds (70 in black lemons, 49 in unripe grapes, and 68 in unripe mango) were identified, and 23 phenolic compounds were quantified using LC-MS/MS. Procyanidin B2, gallic acid, epicatechin, caffeic acid, quercetin, and chlorogenic acid were measured with higher concentration in these selected unripe fruits. A positive correlation was found between phenolic contents and the antioxidant activities of unripe fruits. Furthermore, chemometric analysis was conducted to validate the results. This study will explore the utilization of these unripe fruits to develop functional and therapeutic foods.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

Sustainable Soil Management: Effects of Clinoptilolite and Organic Compost Soil Application on Eco-Physiology, Quercitin, and Hydroxylated, Methoxylated Anthocyanins on Vitis vinifera

Climate change and compostinS1g methods have an important junction on the phenological and ripening grapevine phases. Moreover, the optimization of these composting methods in closed-loop corporate chains can skillfully address the waste problem (pomace, stalks, and pruning residues) in viticultural areas. Owing to the ongoing global warming, in many wine-growing regions, there has been unbalanced ripening, with tricky harvests. Excessive temperatures in fact impoverish the anthocyanin amount of the must while the serious water deficits do not allow a correct development of the berry, stopping its growth processes. This experiment was created to improve the soil management and the quality of the grapes, through the application of a new land conditioner (Zeowine) to the soil, derived from the compost processes of industrial wine, waste, and zeolite. Three treatments on a Sangiovese vineyard were conducted: Zeowine (ZW) (30 tons per ha), Zeolite (Z) (10 tons per ha), and Compost (C) (20 tons per ha). During the two seasons (2021-2022), measurements were made of single-leaf gas exchange and leaf midday water potential, as well as chlorophyll fluorescence. In addition, the parameters of plant yield, yeast assimilable nitrogen, technological maturity, fractionation of anthocyanins (Cyanidin-3-glucoside, Delphinidin-3-glucoside, Malvidin-3-acetylglucoside, Malvidin-3-cumarylglucoside, Malvidin-3-glucoside, Peonidin-3-acetylglucoside, Peonidin-3-cumarylglucoside, Peonidin-3-glucoside, and Petunidin-3-glucoside), Caffeic Acid, Coumaric Acid, Gallic Acid, Ferulic Acid, Kaempferol-3-O-glucoside, Quercetin-3-O-rutinoside, Quercetin-3-O-glucoside, Quercetin-3-O-galactoside, and Quercetin-3-O-glucuronide were analyzed. The Zeowine and zeolite showed less negative water potential, higher photosynthesis, and lower leaf temperature. Furthermore, they showed higher levels of anthocyanin accumulation and a lower level of quercetin. Finally, the interaction of the beneficial results of Zeowine (soil and grapevines) was evidenced by the embellishment of the nutritional and water efficiency, the minimizing of the need for fertilizers, the closure of the production cycle of waste material from the supply chain, and the improvement of the quality of the wines.

Replacement of SO2 with an Unripe Grape Extract and Chitosan during Oak Aging: Case Study of a Sangiovese Wine

The aim of this study was to evaluate the chemical, microbiological and sensory characteristics of a Sangiovese wine aged in barrique with the addition of an unripe grape extract (UGE) as an alternative to sulfur dioxide. Three samples were considered: control wine (TQ) with free SO₂ of approximately 15 mg/L; sample A with chitosan (100 mg/L) and UGE (200 mg/L); and sample B with UGE (400 mg/L). The results achieved in this work demonstrated that the UGE, either alone or in combination with chitosan, was able to maintain the color characteristics of the Sangiovese wine and its sensory quality. Moreover, the addition of UGE contributed to an early and better stabilization of the color through the formation of polymeric pigments. The microbiological stabilization was comparable to SO₂ when UGE was used at 200 mg/L in combination with chitosan. The market survey conducted in the present study confirmed how the use of UGE as an alternative to sulfitation was positively accepted by consumers, who are increasingly attentive not only to the quality of the wines they select but also to the sustainability of the production processes from which they derive and to the fact that they are not harmful to human health.

Green Extraction Technology of Polyphenols from Food By-Products

The development of environmentally friendly approaches to produce high-added value compounds is a field of research that has attracted the interest of the scientific community and several industries such as the food and cosmetic industry [...]

Inhibitory activities of grape bioactive compounds against enzymes linked with human diseases

A quest for identification of novel, safe and efficient natural compounds, as additives in the modern food and cosmetic industries, has been prompted by concerns about toxicity and side effects of synthetic products. Plant phenolic compounds are one of the most documented natural products due to their multifarious biological applications. Grape (Vitis vinifera) is an important source of phenolic compounds such as phenolic acids, tannins, quinones, coumarins and, most importantly, flavonoids/flavones. This review crisply encapsulates enzyme inhibitory activities of various grape polyphenols towards different key human-ailment-associated enzymes: xanthine oxidase (gout), tyrosinase (hyperpigmentation), α-amylase and α-glucosidase (diabetes mellitus), pancreatic lipase (obesity), cholinesterase (Alzheimer's disease), angiotensin i-converting enzymes (hypertension), α-synuclein (Parkinson's disease) and histone deacetylase (various diseases). The review also depicts the enzyme inhibitory mechanism of various grape polyphenols and briefly discusses their stature as potential therapeutic and drug development candidates. KEY POINTS: • Nineteen major bioactive polyphenols from the grape/grape products and their disease targets are presented • Sixty-two important polyphenols as enzyme inhibitors from grape/grape products are presented • A thorough description and graphical presentation of biological significance of polyphenols against various diseases.

Antioxidant Activity and Anti-Apoptotic Effect of the Small Molecule Procyanidin B1 in Early Mouse Embryonic Development Produced by Somatic Cell Nuclear Transfer

As an antioxidant, procyanidin B1(PB1) can improve the development of somatic cell nuclear transfer (SCNT) embryos; PB1 reduces the level of oxidative stress (OS) during the in vitro development of SCNT embryos by decreasing the level of reactive oxygen species (ROS) and increasing the level of glutathione (GSH) and mitochondrial membrane potential (MMP). Metabolite hydrogen peroxide (H₂O₂) produces OS. Catalase (CAT) can degrade hydrogen peroxide so that it produces less toxic water (H₂O) and oxygen (O₂) in order to reduce the harm caused by H₂O₂. Therefore, we tested the CAT level in the in vitro development of SCNT embryos; it was found that PB1 can increase the expression of CAT, indicating that PB1 can offset the harm caused by oxidative stress by increasing the level of CAT. Moreover, if H₂O₂ accumulates excessively, it produces radical-(HO-) through Fe^2+/3+ and damage to DNA. The damage caused to the DNA is mainly repaired by the protein encoded by the DNA damage repair gene. Therefore, we tested the expression of the DNA damage repair gene, OGG1. It was found that PB1 can increase the expression of OGG1 and increase the expression of protein. Through the above test, we proved that PB1 can improve the repairability of DNA damage. DNA damage can lead to cell apoptosis; therefore, we also tested the level of apoptosis of blastocysts, and we found that PB1 reduced the level of apoptosis. In summary, our results show that PB1 reduces the accumulation of H₂O₂ by decreasing the level of OS during the in vitro development of SCNT embryos and improves the repairability of DNA damage to reduce cell apoptosis. Our results have important significance for the improvement of the development of SCNT embryos in vitro and provide important reference significance for diseases that can be treated using SCNT technology.

Potential opportunities of thinned clusters in viticulture: a mini review

Crop thinning is a common practice performed in the vineyard consisting of whole clusters or individual fruits being removed after flowering is attained. Current studies have reported that unripe grape products as verjuice and sour grape sauce contain high content of bioactive compounds such as polyphenols, sugars, organic acids, nitrogenous compounds and sterols. This mini-review overviewed the bioactive components obtained from thinned unripe grapes such as phenolic compounds, sugars, organic acids, minerals, nitrogen compounds and sterols, and their use as antibrowning and whitening agents, natural catalysts, food preservative and food additive. In addition, their beneficial effects for human health also were reviewed, as well as the practices to maximize the extraction of antioxidant compounds. Therefore, revalorizing the waste from this management practice in viticulture can increase the vineyard sustainability and farmers' economic profits. © 2021 Society of Chemical Industry.

Comprehensive Utilization of Thinned Unripe Fruits from Horticultural Crops

Fruit thinning is a cultivation technique that is widely applied in horticulture in order to obtain high-quality horticultural crops. This practice results in the discarding of a large number of thinned unripe fruits in orchards each year, which produces a great waste of agricultural resources and causes soil pollution that may be an important reservoir for pest and plant diseases. Current studies showed that bioactive compounds such as polyphenols, organic acids, monosaccharides and starches are present in unripe fruits. Therefore, we reviewed the bioactive components obtained from thinned unripe fruits, their revalorization for the food industry, their beneficial effects for human health and the methods for obtaining these components. We also performed a calculation of the costs and benefits of obtaining these bioactive compounds, and we proposed future research directions. This review provides a reference for the effective utilization and industrial development of thinned unripe fruits obtained from horticultural crops. Furthermore, revalorizing the waste from this cultural practice may increase the economic benefits and relieve the environmental stress.

Characterisation of Extracts Obtained from Unripe Grapes and Evaluation of Their Potential Protective Effects against Oxidation of Wine Colour in Comparison with Different Oenological Products

Unripe grapes (UGs) are a waste product of vine cultivation rich in natural antioxidants. These antioxidants could be used in winemaking as alternatives to SO2. Three extracts were obtained by maceration from Viognier, Merlot and Sangiovese UGs. The composition and antioxidant activity of the UG extracts were studied in model solutions at different pH levels. The capacity of the UG extracts to protect wine colour was evaluated in accelerated oxidation tests and small-scale trials on both red and white wines during ageing in comparison with sulphur dioxide, ascorbic acid and commercial tannins. The Viognier and Merlot extracts were rich in phenolic acids while the Sangiovese extract was rich in flavonoids. The antioxidant activity of the extracts and commercial tannins was influenced by the pH. In the oxidation tests, the extracts and commercial products showed different wine colour protection capacities in function of the type of wine. During ageing, the white wine with the added Viognier UG extract showed the lowest level of colour oxidation. The colour of the red wine with the UG extract evolved similarly to wine with SO2 and commercial tannins. The obtained results indicated that natural and healthy UG extracts could be an interesting substitute for SO2 during wine ageing.

Phenolic Compounds From Brewer's Spent Grains: Toward Green Recovery Methods and Applications in the Cosmetic Industry

Brewers' spent grain (BSG) is the main by-product derived from the brewing industry, where it accounts for 85% of the total waste generated. The total annual production worldwide of this waste is 39 million tons. This lignocellulosic material is traditionally used as cattle feed and sold at a low retail price (~USD 45.00 per ton). However, efforts for the revalorization of this by-product are emerging since research has established that it can be used as a low-cost source of bioactive molecules and commodity chemicals that can bring value to integral biorefinery ventures. Among commodities, phenolic compounds have attracted attention as added-value products due to their antioxidant properties with applications in the food, cosmetic, and pharmaceutical industries. These phytochemicals have been associated with antiaging and anticancer activities that have potential applications on cosmetic products. This mini-review summarizes the most relevant extraction techniques used for the recovery of phenolic compounds from BSG while discussing their advantages and shortcomings and the potential applications from BSG bioactive extracts in the cosmetic industry and their reported beneficial effects. This mini-review also makes a brief comment on the role of phenolic compounds extraction in the economic feasibility of an integral BSG biorefinery.

Caftaric Acid Isolation from Unripe Grape: A "Green" Alternative for Hydroxycinnamic Acids Recovery

Phenolic acids represent about one-third of the dietary phenols and are widespread in vegetable and fruits. Several plants belonging to both vegetables and medical herbs have been studied for their hydroxycinnamic acid content. Among them, Echinacea purpurea is preferentially used for caffeic acid-derivatives extraction. The wine industry is a source of by-products that are rich in phenolic compounds. This work demonstrates that unripe grape juice (verjuice) presents a simple high-pressure liquid chromatography (HPLC) profile for hydroxycinnamic acids (HCAs), with a great separation of the caffeic-derived acids and a low content of other phenolic compounds when compared to E. purpurea and other grape by-products. Here it is shown how this allows the recovery of pure hydroxycinnamic acids by a simple and fast method, fast protein liquid chromatography (FPLC). In addition, verjuice can be easily obtained by pressing grape berries and filtering, thus avoiding any extraction step as required for other vegetable sources. Overall, the proposed protocol could strongly reduce the engagement of solvent in industrial phenolic extraction.

Winemaking Byproducts as Source of Antioxidant Components: Consumers' Acceptance and Expectations of Phenol-Enriched Plant-Based Food

One of the food industry's priorities is to recover byproducts and move towards more sustainable systems. Among wine-chain byproducts, unripe grapes represent a promising source of antioxidants. However, the development of new foods enriched using phenol-rich ingredients is challenging due to their sensory attributes. The aims of the present study were to (1) use phenol-rich extract from unripe grapes to enrich a model plant-based food (beetroot puree-BP); (2) evaluate consumers' acceptance and expectations for the beetroot purée samples. The effect of information about the sustainability and pro-health activity of value-added ingredients on consumers' responses was also investigated. Four beetroot purees with increasing concentrations of phenol extract (0-1.93 g/kg) added were evaluated by 101 participants in three tasting conditions (blind: only samples; expected: only information without tasting; real: both samples and information).Liking slightly decreased with increasing concentrations of phenol extract, even if all the samples were considered acceptable. The health and sustainability information increased the hedonic expectations, although it was not assimilated by all consumers involved. The development of new phenol-enriched foods using functional ingredients from unripe grapes is challenging. However, it is also promising, since all the samples were generally accepted by the consumers and they presented phenol levels that were stable over time and that could have positive health effects when consumed.

Effect of Four Grape Varieties on the Physicochemical and Sensory Properties of Unripe Grape Verjuice

Verjuice is a sour-tasting juice obtained from the mechanical pressing of unripe grapes. The significance of verjuice as food product includes but not limited to its richness in antioxidant compounds, its usage as an alternative to lemon and vinegar, and also its production which can reduce the losses of lower quality grapes and waste from grape thinning. In this study, a survey for the common Lebanese traditional preparation methods for verjuice was done and physicochemical properties of four Lebanese verjuice varieties Tfayfihi, Baytamoni, Black, and Obeideh along with their sensory evaluation by consumers were studied. Results showed that "Black" grape verjuice has the highest density (1.01 ± 0.003 g/L), titratable acidity (4.51 g/L ± 0.03), total soluble solids (5.38°Brix ± 0.3), and polyphenol content (676.1 mg/L ± 6.8); verjuice processed from the Baytamoni grape variety has the highest browning index (0.432 ± 0.002) and color intensity (1.18 ± 0.007); "Obeideh" grape verjuice has the highest pH (2.55 ± 0.006); and "Tfayfihi" grape verjuice has the highest radical scavenging potential (91.76% ± 0.43) and moisture content (95.85% ± 0.19). Both "Tfayfihi" and "Black" grape verjuice has the highest total suspended solids (40 g/L ± 1.3 and 40 g/L ± 2.9, respectively) among all studied verjuice. There is no difference in taste between the four verjuice varieties which we studied, but there is a color preference for the "Tfayfihi" verjuice. The use of different varieties of grapes in the processing of verjuice affects the physicochemical and sensory properties and results in selection of grape varieties being favorable in the processing of verjuice with respect to factors such as polyphenol content and color of the final product.