Milk kefir enriched with inulin‐grafted seed extract from white wine pomace: chemical characterisation, antioxidant profile and in vitro gastrointestinal digestion

Rheological, microbiological, and in vitro digestive properties of Kefir produced with different Kefir grains and commercial starter cultures

This research investigates the production of kefir using Turkish and Kazakh kefir grains and commercial starter cultures, followed by storage at 4 °C for 30 days. The study monitors the rheological properties and microbiological characteristics of kefir on the 1st, 15th, and 30th days of storage, as well as during dynamic in vitro gastrointestinal digestion. Kefir samples were passed through a dynamic in vitro gastrointestinal model simulating the digestive processes of the mouth, stomach, and small intestine which was designed in laboratory conditions. Kefir from Turkish kefir grain exhibited the lowest average titratable acidity, apparent viscosity, and flow behavior index, while kefir from Kazakh kefir grain had the highest average pH. Over the storage period, pH and flow behavior index decreased, while titratable acidity, viscosity, and consistency coefficient increased. The kefir samples showed non-Newtonian pseudoplastic flow characteristics. The acetic acid bacteria and Leuconostoc counts of kefir samples produced with commercial starter cultures were higher than those produced with kefir grains, while yeast counts were higher in kefir samples produced with kefir grains. During storage and in vitro gastrointestinal digestion, the number of microorganisms in kefir samples decreased. Turkish kefir grain resulted in the lowest reduction (%) of microorganism counts during in vitro gastrointestinal digestion. These findings shed light on the rheological, microbiological, and in vitro digestive properties of kefir during storage, which may contribute to improving the quality and health benefits of kefir products. The present study revealed that the kefir produced with kefir grains had a lower decrease in the viability of microorganisms compared to the kefir produced with starter culture after passage through the gastrointestinal model, so kefir produced with kefir grains may be more preferred due to its possible health benefits.

Carob pulp flour as an innovative source of bioactive molecules for the preparation of high-value-added jellies

The rising demand for healthier alternatives to traditional sugary products has driven the exploration of natural substitutes for sucrose. This study aimed to investigate carob pulp flour (CPF) as a viable alternative to sucrose in the production of high-value jellies with enhanced health benefits. Carob pulp flour was spectroscopically characterized, revealing the presence of bioactive molecules, such as natural antidiabetic polyols and polyphenols. Colorimetric tests demonstrated a significant concentration of polyphenolic molecules in CPF, with a remarkable scavenging activity against radical species in both organic and aqueous environments. Jellies based on CPF (CGC) were successfully prepared and exhibited strong antioxidant activity against ABTS (IC50 0.158 mg mL-1) and DPPH (IC50 0.175 mg mL-1) radicals, maintaining their properties over 15 days, unlike the sucrose-based control, which showed no antioxidant activity. The CPF-enhanced jellies consistently demonstrated higher G' values (in the range 20-35 °C) than the sucrose-based jellies, indicating improved consistency, elasticity, and strong gel properties, even at higher temperatures. Sensory analysis revealed significant differences, with CPF-based jellies displaying enhanced chocolate (2.3 ± 1.0), ripe fruit (2.3 ± 1.8), and caramel odors (2.0 ± 0.9), as well as increased bitterness and astringency, reduced sweetness, and improved texture. Additionally, CPF-based jellies exhibited significant hypoglycemic properties, with dose-dependent inhibitory effects on α-amylase (57.7 %) and α-glucosidase (50.3 %), and a moderate lipase inhibitory effect (48.6 %) at the maximum concentrations tested. The findings of this study highlight the potential of CPF as a functional ingredient in the food industry, offering a healthier alternative to sucrose in jelly production. The inclusion of CPF not only enhances the antioxidant and sensory properties of jellies but also contributes to significant hypoglycemic effects, making it a promising candidate for the development of functional foods with added health benefits.

Advances in Food Waste Biomass Transformation into High-Value Products

In recent years, there has been a concerning surge in waste generation, with agri-food waste emerging as a significant issue across various stages of the food supply chain [...].

Study and characterization of a product based on a vegetable extract of quinoa fermented with water kefir grains

This work aimed to study and characterize a product based on vegetable extract of quinoa (WVEQ) fermented with water kefir grains. The effect of sucrose concentration (SC), inulin concentration (IC), and xanthan gum (XG) concentration were evaluated using a central composite design (CCD) 23. They were subsequently characterized regarding cellular growth of the grains, beverage yield, pH, soluble solids, carbon dioxide (CO2) production, lactic acid, and ethanol production. Therefore, for the final stage, two formulations (F1 and F8) of the CCD were chosen to be characterized in terms of proximate composition, microbiological composition of the kefir culture, analysis of organic compounds, sensory analysis, and enzymatic and microbiological characterization before and after simulation of in vitro gastrointestinal digestion. In the two chosen products, one can see that fermentation optimized the bioavailability of proteins due to the high proteolytic activity of the microorganisms in kefir and the increase in lipid content. In identifying microorganisms, there was a prevalence of Saccharomyces sp. yeasts. In the sensory analysis, the F8 formulation showed better results than the F1 formulation. In vitro, gastrointestinal digestion showed reduced lactic acid bacteria and yeast and increased acetic acid bacteria in the liquid phase for both formulations. In the enzymatic profile, there was a reduction in all enzymes analyzed for both formulations, except for amylase in F1, which went from 14.05 U/mL to 39.41 U/mL. Therefore, it is concluded that using WVEQ as a substrate for the product appears to be a viable alternative with nutritional and technological advantages for serving a specific market niche.

A medical and molecular approach to kefir as a therapeutic agent of human microbiota

The imbalanced microbial composition called dysbiosis constitutes a tendency related to different kind of human diseases. To overcome the disadvantages of dysbiosis, the consumption of probiotics is an emerging and promising topic of the last decade. Kefir is a probiotic fermented beverage produced from the fermentation of kefir grains with changing varieties of milk and displays a symbiotic association of bacteria and yeast. The discovery of the concept that fermented foods/beverages such as kefir could modify gut microbiota in humans has widened the borders of precision medicine and now microbiome therapeutics can be considered as a significant part of this field. Kefir seems to have potential to guide and manipulate future replacement/complementary therapies with a variety of beneficial biological/medical properties it has. The aim of this review was a comprehensive recapitulation of probiotic beverage kefir's significant properties mainly focusing of antioxidative, immunomodulatory, apoptotic, antitumor and neuroprotective properties. Apoptotic/antimetastatic effects are regulated at the molecular level by increases in TGF-β1, caspase-3, p53, Bax, Bax:Bcl-2 ratio, p21 and decreases in TGF-α, Bcl-2 and MMP polarization. Neuroprotective effects are revealed upon upregulation of SOD/catalase and anti-inflammatory Treg cells, decreases in repetitive behavior and modulation of apoptotic genes. Besides these significant features that may offer advantages in supplementary cancer therapies, the scope was also extended to recent emerging medical topics and also discussed and evaluated the concept of "psychobiotics". The therapeutic potential of psychobiotic effect is majorly attributed to the increased ratios of Clostridium butyricum, Lactobacillus and Bifidobacterium.

Formulation of Antioxidant Gummies Based on Gelatin Enriched with Citrus Fruit Peels Extract

In this work, the peels of red and blonde oranges as well as lemons were efficiently (5.75-9.65% yield) extracted by hydroalcoholic solution with ultrasound assistance and employed as active molecule sources in the preparation of functional gummies. Antioxidant performances of the hydroalcoholic extracts were characterized by colorimetric assays, whereas LC-HRMS analyses identified the main bioactive compounds (phenolic acids and flavonoids). The highest scavenging activity was recorded for lemon extract in an aqueous environment (IC50 = 0.081 mg mL-1). An ecofriendly grafting procedure was performed to anchor polyphenols to gelatin chains, providing macromolecular systems characterized by thermal analysis and antioxidant properties. Scavenger abilities (IC50 = 0.201-0.454 mg mL-1) allowed the employment of the conjugates as functional ingredients in the preparation of gummies with remarkable antioxidant and rheological properties over time (14 days). These findings confirmed the possible employment of highly polluting wastes as valuable sources of bioactive compounds for functional gummies preparation.

Wine Lees as Source of Antioxidant Molecules: Green Extraction Procedure and Biological Activity

An ultrasound-assisted extraction method, employing ethanol and water as solvents at low temperature (30 °C) and reduced time (15 min), was proposed to extract bioactive molecules from different cultivars (Magliocco Canino, Magliocco Rosato, Gaglioppo, and Nocera Rosso) of wine lees. All the extract yields were evaluated and their contents of phenolic acids, flavonoids, and total polyphenols were determined by means of colorimetric assays and high-performance liquid chromatography coupled with diode-array detection (HPLC-DAD) and Fourier transform infrared (FTIR) techniques. Radical scavenging assays were performed and the Magliocco Canino extracted with a hydroalcoholic mixture returned the best results both against ABTS (0.451 mg mL−1) and DPPH (0.395 mg mL−1) radicals. The chemometric algorithms principal component analysis (PCA) and partial least square regression (PLS) were used to process the data obtained from all qualitative–quantitative sample determinations with the aim of highlighting data patterns and finding possible correlations between composition and antioxidant features of the different wine lees cultivars and the extraction procedures. Wine lees from Magliocco Canino and Magliocco Rosato were found to be the best vegetable matrices in terms of metabolite content and antioxidant properties. The components extracted with alcoholic or hydroalcoholic solvents, specifically (−)-epigallocatechin gallate, chlorogenic acid, and trans-caftaric acid, were found to be correlated with the antioxidant capacity of the extracts. Multivariate data processing was able to identify the compounds related to the antioxidant features. Two PLS models were optimized by using their concentration levels to predict the IC50 values of the extracts in terms of DPPH and ABTS with high values of correlation coefficient R2, 0.932 and 0.824, respectively, and a prediction error lower than 0.07. Finally, cellular (SH-SY5Y cells) antioxidant assays were performed on the best extract (the hydroalcoholic extract of Magliocco Canino cv) to confirm its biological performance against radical species. All these recorded data strongly outline the aptness of valorizing wine lees as a valuable source of antioxidants.

The Protective Role of Grape Seed in Obesity and Lipid Profile: An Updated Narrative Overview of Preclinical and Clinical Studies

Obesity and dyslipidemia are common disorders universally. According to the acquired outcomes of recent studies, dietary supplementations which have great content of phenolic compounds exert protective effects against obesity and dyslipidemia. Grape [Vitis vinifera] seeds are considered attractive sources of phenolic compounds with anti-oxidative stress and anti-inflammatory effects. There are also various experimental studies describing hepatoprotective, neuroprotective, anti-aging, cardioprotective, and anti-carcinogenic effects of polyphenols isolated from grape seed, highlighting the therapeutic and biological aspects of proanthocyanidins. The present review article first discusses pharmacological, botanical, toxicological, and phytochemical characteristics of Vitis vinifera seeds and afterward designates the protective properties which are attributed to the intake of grape seeds in obesity and hyperlipidemia. Overall valuable and updated findings of this study display that polyphenol of grape seeds has meaningful impacts on the regulation of lipid profile levels and management of obesity.