Pressurized liquid extraction of bioactive compounds from grape peel and application in pH-sensing carboxymethyl cellulose films: A promising material to monitor the freshness of pork and milk.

This study produced pH-sensing carboxymethyl cellulose (CMC) films functionalized with bioactive compounds obtained by pressurized liquid extraction (PLE) of grape peel to monitor the freshness of pork and milk. A semi-continuous PLE was conducted using hydroethanolic solution (70:30, v/v) at a flow rate of 5 mL/min, 15 MPa, and 60 °C. The films were produced by the casting technique using CMC (2.5 %, w/v), glycerol (1 %, v/v), and functionalized with 10, 30, and 50 % (v/v) grape peel extract. From the results obtained, LC-MS/MS revealed that PLE extracted twenty-seven phenolic compounds. The main phenolic compounds were kaempferol-3-glucoside (367.23 ± 25.88 µg/mL), prunin (270.23 ± 3.62 µg/mL), p-coumaric acid (236.43 ± 26.02 µg/mL), and procyanidin B1 (117.17 ± 7.29 µg/mL). The CMC films presented suitable color and mechanical properties for food packaging applications. The addition of grape peel extract promoted the pH-sensing property, showing the sensitivity of anthocyanins to pH changes. The films functionalized with grape peel extract presented good release control of bioactive compounds, making them suitable for food packaging applications. When applied to monitor the freshness of pork and milk, the films exhibited remarkable color changes associated with the pH of the food during storage. In conclusion, PLE is a sustainable approach to obtaining bioactive compounds from the grape peel, which can be applied in the formulation of pH-sensing films as a promising sustainable material to monitor food freshness during storage.

Fighting coronaviruses with natural polyphenols.

Few licensed drugs and vaccines are available concerning COVID-19, a disease caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2). Furthermore, numerous recent SARS-COV-2 variants of have arisen globally, demonstrating the need to develop broadly protective interventions for different coronavirus strains. Polyphenols are the largest class of natural bioactive compounds, categorized as flavonoids (catechins, quercetin and kaempferol) and non-flavonoids (gallic acid and resveratrol), and these compounds have been described as effective antiviral agents. This is because they can inhibit coronavirus enzymes, blocking replication and infection. The present short manuscript aimed to summarize and report the current evidence from well-known powerful flavonoid (catechin, quercetin, and kaempferol) and non-flavonoid (gallic acid and resveratrol) polyphenols obtained from plant extracts that inhibit coronavirus strains in in vitro models or by computer modeling. The knowledge of strategies beyond conventional treatments may be helpful in the development of new coronavirus drugs, treatments/medicines, or formulations.

Application in situ of biodegradable films produced with starch, citric pectin and functionalized with feijoa (Acca sellowiana (Berg) Burret) extracts: An effective proposal for food conservation.

In this study, biodegradable films produced with starch, citric pectin, and functionalized with antioxidant compounds from feijoa (Acca sellowiana (Berg) Burret) were in situ applied for the conservation of ground beef, bread, and grapes. The results demonstrated that the films produced were an excellent source of stable antioxidant compounds, with antimicrobial activity against Escherichia coli, Salmonella, and Shigella. The bioactive films based on biological macromolecules positively stabilized the polyunsaturated fatty acids and deterioration reactions in ground beef. The release of bioactive compounds from the films was responsible for inhibiting molds and yeasts in bread, increasing their shelf life for 30 days of storage. The application of film coating and packaging in grapes increased postharvest conservation and maintained steady physicochemical characteristics. Therefore, the innovative films produced can release bioactive compounds with antioxidant and antimicrobial activity, and consequently, can be proposed as an effective material for food conservation, increasing the shelf life of perishable food products.

Volatile Compounds Determined by SPME-GC, Bioactive Compounds, In Vitro Antioxidant Capacity and Physicochemical Characteristics of Four Native Fruits from South America.

The aim of the present study was to identify volatile organic compounds (VOCs) by SPME-GC and quantify the bioactive compounds (ascorbic acid, total flavonoids and total phenolic content), antioxidant capacity (DPPH and ORAC) and physicochemical characteristics of ocorocillo, cambucá, murici da praia and murici do campo, four native South American fruits. A total of 41 volatile compounds were identified in ocorocillo, of which 17 were terpenes. Cambuca's volatile profile contained aldehydes, aromatic hydrocarbons and alcohols. Murici da praia and murici do campo contained high levels of fatty acid volatiles and esters, that contribute to their remarkable aroma. Ocorocillo contained high levels of ascorbic acid and total flavonoids, while cambucá presented lower ascorbic acid, flavonoid and phenolic levels. Murici da praia and murici do campo contained high amounts of phenolic compounds and high free-radical scavenging capacity (DPPH and ORAC). In addition, this fruit was sweeter and less acid compared to the other assessed fruits. The results suggest that these native fruits constitute a good source of volatile compounds and bioactive compounds, which may aid in their preservation interest and potential use in the food, cosmetic and pharmaceutical industries.

Chemical composition, nutritional value and bioactive compounds in six uvaia accessions.

This study analyzed six uvaia (Eugenia pyriformis Cambess) accessions ('Comum', 'Rugosa', 'Doce de Patos de Minas', 'Pêra', 'Rugosa Doce' and 'Dura') with respect to chemical composition, nutritional value, bioactive compounds and antioxidant capacity. The 'Rugosa Doce' and 'Doce de Patos de Minas' accessions were sweeter (20.18 g 100 g-1 and 18.88 g 100 g-1, respectively), while the 'Rugosa' and 'Pêra' accessions were less acid (0.28 g 100 g-1 and 0.33 g 100 g-1, respectively). Terpenes were the major volatile compounds (46.75%) identified by SPME-GC/MS. The 'Rugosa' accession contained high levels of fibers (43.81 g 100 g-1) and minerals (2235.10  mg 100 g-1). The 'Rugosa Doce' and 'Rugosa' accessions were distinguished by total flavonoids and phenolic compounds. 'Rugosa Doce' and 'Rugosa' may potentially serve as a raw material for food, while 'Doce de Patos de Minas' and 'Pêra' can be used for cosmetic and pharmaceutical industries purposes.