Polyphenol Composition by HPLC-DAD-(ESI-)MS/MS and Bioactivities of Extracts from Grape Agri-Food Wastes.

BACKGROUND: Grape agri-food wastes, such as skin, seeds, and other discarded by-products, contain phytochemical compounds that offer potential health benefits. METHODS: This study aimed to investigate the polyphenol composition and bioactivities of different extracts obtained from grape marc and seeds, with the goal of exploring their potential for application as natural food additives. RESULTS: Regardless of the extraction method used (dynamic maceration, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE)), all extracts exhibited relatively high concentrations of phenolic compounds. The chemical characterization of the extracts revealed the presence of specific compounds and chemical groups associated with each extraction methodology. Moreover, the extracts displayed satisfactory antioxidant activities, especially in inhibiting lipoperoxidation as assessed by the TBARS assay. Additionally, the extracts demonstrated effective inhibition against different strains of bacteria and fungi known as food contaminants. Taken together, these findings indicate that those extracts have the potential to be tested as natural antioxidants and preservatives with sustainable origins in food and beverage systems. Among the extraction methods evaluated, traditional maceration and UAE provided extracts with the highest antioxidant and antimicrobial activities. CONCLUSIONS: Our results suggest the opportunity to explore grape marc and seeds discarded by the winery industry in Portugal as natural sources of bioactive compounds, which could be employed as functional food ingredients or technological additives. The valorization of grape biowastes offers a promising strategy to reduce waste and harness their potential health benefits.

Emerging Strategies to Combat Methicillin-resistant Staphylococcus aureus (MRSA): Natural Agents with High Potential.

Infectious diseases have always been a concern for human health, responsible for numerous pandemics throughout history. Even with the advancement of medicine, new infectious diseases have been discovered over the years, requiring constant effort in medical research to avoid future problems. Like the emergence of new diseases, the increase in resistance of certain bacterial strains also becomes a concern, carried out through the misuse of antibiotics, generating the adaptation of certain microorganisms. Worldwide, the resistance developed by several bacterial strains is growing exponentially, creating awareness and developing novel strategies to control their evolution a mandatory research topic. Methicillin-resistant Staphylococcus aureus (MRSA) is an example of a bacterial strain that causes serious and mortal infections. The fact is that this bacterial strain started to develop resistance against commonly used antibiotics, first to penicillin and against methicillin. Thus, the treatment against infections caused by MRSA is limited and difficult due to its capacity to develop defense mechanisms against the antibiotic's action. Given the urgency to find new alternatives, the scientific community has been developing interesting research regarding the exploitation of natural resources to discover bioactive molecules that are able to inhibit/kill MRSA. In this sense, several natural matrices, namely plants, have shown great potential against MRSA, due to the presence of phenolic compounds, molecules with high antimicrobial capacity due to their chemical structure and arrangement.

Improving the physicochemical properties of a traditional Portuguese cake - "económicos" with chestnut flour.

"Económicos" are traditional Portuguese pastry products; although their production is low-cost, their nutritional value is equally low. Since it is a widely consumed product in the Trás-os-Montes region, it is important to add value to it without making significant changes to the traditional recipe. Thus, this work has the main objective to increase the nutritional power of "económicos" through the incorporation of chestnut (Castanea sativa) fruit flour. The influence of the incorporation of 9% of chestnut flour as a new ingredient was analysed in terms of physical parameters (texture, colour, pH, water activity and moisture), nutritional content (according to the official AOAC methodology) and chemical parameters (sugars, fatty acids and organic acids) and the ability to control the microbial load over shelf life (32 days). Overall, the addition of the chestnut flour did not drastically change the appearance of the chemical and physical profiles of the cakes, but resulted in a lighter crumb (L*), slight changes in the texture profile, reduction of fat, and most importantly, introduced healthier flour to this inexpensive cake. Moreover, it did not stimulate the growth of microorganisms (total aerobic mesophiles, coliforms, Bacillus cereus, molds, and yeasts) during the 32 days of storage.

Promising Preserving Agents from Sage and Basil: A Case Study with Yogurts.

In the present work, sage (Salvia officinalis L.) and basil (Ocimum basilicum L.) were exploited for their preservative purposes, as viable alternatives to artificial ones. The ultrasound-assisted extraction (UAE) of bioactive compounds was pre-optimized using factorial screening analysis, prior to applying response surface methodology (RSM). The obtained extracts were characterized in terms of phenolic compounds by high-performance liquid chromatography coupled to photodiode array detector and mass spectrometer HPLC-DAD-ESI/MS and bioactivities, namely the antioxidant, antimicrobial and cytotoxic potential. In addition, the most promising extracts were incorporated into yogurts, that were further screened for nutritional and physico-chemical properties and microbial load, over a shelf life of 14 days. According to the obtained results, the solvent percentage is the most relevant factor for obtaining rosmarinic acid-rich extract, followed by the extraction time and ultrasonic power. For the antioxidant and antimicrobial activity, sage showed the best result for both analysis and none of the two plant extracts were hepatotoxic. Finally, both extracts did not show changes in the physicochemical and nutritional characteristics of the yogurts and did not interfere with the growth of lactic acid bacteria, an important microorganism during yogurt fermentation. These results highlight the high potential of sage and basil as natural preservatives.

Preservation of Chocolate Muffins with Lemon Balm, Oregano, and Rosemary Extracts.

Muffins are snacks made from flour and chocolate and preserved with synthetic additives. Following consumer trends, the search for natural food additives has gained traction. Plants such as rosemary, lemon balm, and oregano were analyzed following an optimization of ultrasound assisted extraction, screened for their antioxidant and antimicrobial activity and incorporated in chocolate muffins, comparing them to synthetic preservatives over the course of 8 days. The nutritional profile, organic and fatty acids, soluble sugars, texture profile, external color and digital imaging of the muffin pores were analyzed. Slight changes were sought for the muffins incorporated with the natural extracts. By means of linear discriminant analysis, rosemary extract was considered the most promising extract to preserve the muffins due to its similarity to potassium sorbate, showing no changes in the muffins it was incorporated in, although it showed a lower amount of phenolic compounds when compared to lemon balm.