A novel metalloprotease from banana peel and its biochemical characterization

A systematic study on the characteristics and applications of laccases produced by fungi: insights on their potential for biotechnologies

Laccases are polyphenol oxidase enzymes and form the enzyme complex known for their role in wood decomposition and lignin degradation. The present study aimed to systematically review the state-of-the-art trends in scientific publications on laccase enzymes of the last 10 years. The main aspects checked included the laccase-producing fungal genera, the conditions of fungal growth and laccase production, the methods of immobilization, and potential applications of laccase. After applying the systematic search method 177 articles were selected to compound the final database. Although various fungi produce laccase, most studies were Trametes and Pleurotus genera. The submerged fermentation (SmF) has been the most used, however, the use of solid-state fermentation (SSF) appeared as a promising technique to produce laccase when using agro-industrial residues as substrates. Studies on laccase immobilization showed the covalent bonding and entrapment methods were the most used, showing greater efficiency of immobilization and a high number of enzyme reuses. The main use of the laccase was in bioremediation, especially in the discoloration of dyes from the textile industry and the degradation of pharmaceutical waste. Implications and consequences of all these findings in biotechnology and environment, as well as the trends and gaps of laccase research were discussed.

Banana Peel (Musa ABB cv. Nam Wa Mali-Ong) as a Source of Value-Adding Components and the Functional Properties of Its Bioactive Ingredients

Banana peel (BP) is the primary by-product generated during banana processing which causes numerous environmental issues. This study examines the physical attributes, proximate analysis, glycoarray profiling, antioxidant abilities, and prebiotic activity of BP. The analysis demonstrated that carbohydrates constituted the primary components of BP and the glycoarray profiling indicated that BP contains multiple pectin and hemicellulose structures. BP also contained phenolic compounds, including (+)-catechin and gallic acid, flavonoid compounds, and antioxidant activities. BP demonstrated prebiotic effects by promoting the proliferation of advantageous gut bacteria while inhibiting the growth of harmful bacteria. The prebiotic index scores demonstrated that BP exhibited a greater capacity to promote the growth of beneficial bacteria in comparison to regular sugar. The study demonstrated the potential of the BP as a valuable source of dietary fibre, bioactive compounds, and prebiotics. These components have beneficial characteristics and can be utilised in the production of food, feed additives, and functional food.

Trends in Sieving and Its Applications in Cereals. A Literature Review

In the agroindustry, sieving is a unit operation of great value, this work aims to make a literature review on sieving in cereals, a search equation was carried out in the Scopus database with the keywords sieve, screen, food process, and cereal that resulted in 132 articles and 174 patents. Of the articles, 44 were directly related to sieving and 14 more had something to do with sieving; of the patents, in the last 10 years only 7 were directly related to sieving. To find new trends, raw materials, patent analysis, and information analysis, tables were built with name, year, author, keywords, countries, quartile, journal, relationship with the agroindustry, and purpose. Among the most important conclusions was the application of sieving in raw materials such as Rice, Corn, Wheat, Cotton, Millet, Quinoa, Almonds, Barley, Potato, Yucca, Microorganisms, Oats, Cotton, Protein, Peppers, and Chia Seed. Furthermore, the use of rotating and vibrating sieves was identified, and also their positive effects on the physicochemical, standardization, and classification of raw materials were identified. The different types of equipment or methods focused on sieving, that has been granted use or design patent, were also recognized.

Whitening efficacy of popular natural products on dental enamel

The objective of this study was to evaluate the effect of natural bleaching products on the color, whiteness, and superficial properties of dental enamel. Seventy fragments of bovine teeth were obtained (6mm x 6mm x 2mm). Initial surface roughness (Surfcorder SE1700, Kosakalab), microhardness (HMV-2, Shimadzu), color (EasyShade, VITA), and surface gloss (Micro-Gloss 45º BYK, Gardner) readings were done. Samples were separated into five groups (n=14) according to the treatments used: CT-conventional toothpaste (negative control); CH-charcoal; TU-turmeric; BP-banana peel, and CP16%-16% carbamide peroxide gel (positive control, 4 h/day for 14 days), and then brushed for 560 cycles (T1) and 1200 cycles (T2), equivalent to 14 and 30 days of brushing. New measurements were performed after T1 and T2. The whiteness index for dentistry change (∆WID) and Weight loss (Wl) were calculated. CP16% demonstrated the highest (p<.05) color change (ΔE00) and ∆WID (2-way ANOVA, Bonferroni, p<.05). Surface gloss alterations were lower for TU, CP16%, and BP. CT and CH increased surface roughness (p<.05). CP16% decreased enamel microhardness. CH presented medium abrasiveness, and CT and TU, low abrasiveness. The popular bleaching products were not efficient for tooth whitening. Furthermore, brushing with charcoal increased the enamel surface roughness, and CP16% decreased enamel microhardness over time.

Fruit peel bioactives, valorisation into nanoparticles and potential applications: A review

Nanotechnology is a rapidly growing field with profound applications in different domains, particularly in food science and technology. Nanoparticles (NPs) synthesis, an integral part of nanotechnology-based applications, is broadly classified into chemical, physical and biosynthesis methods. Chemically sensitive and energy-intensive procedures employed for NPs synthesis are some of the limits of traditional chemical approaches. Recent research has focused on developing easy, nontoxic, cost-effective, and environment-friendly NPs synthesis during the last decade. Biosynthesis approaches have been developed to achieve this goal as it is a viable alternative to existing chemical techniques for the synthesis of metallic nanomaterials. Fruit peels contain abundant bioactive compounds including phenols, flavonoids, tannins, triterpenoids, steroids, glycosides, carotenoids, anthocyanins, ellagitannins, vitamin C, and essential oils with substantial health benefits, anti-bacterial and antioxidant properties, generally discarded as byproduct or waste by the fruit processing industry. NPs synthesized using bioactive compounds from fruit peel has futuristic applications for an unrealized market potential for nutraceutical and pharmaceutical delivery. Numerous studies have been conducted for the biosynthesis of metallic NPs such as silver (AgNPs), gold (AuNPs), zinc oxide, iron, copper, palladium and titanium using fruit peel extract, and their synthesis mechanism have been reported in the present review. Additionally, NPs synthesis methods and applications of fruit peel NPs have been discussed.

Conversion of Pectin-Containing By-Products to Pectinases by Bacillus amyloliquefaciens and Its Applications on Hydrolyzing Banana Peels for Prebiotics Production

The utilization of pectin-containing by-products may be useful in a variety of fields. This study aims to establish the processing of pectin-containing by-products to produce pectinases using Bacillus amyloliquefaciens TKU050 strain. In this study, several kinds of agricultural pectin-containing by-products from banana (banana peel), rice (rice bran), orange (orange peel), coffee (spent coffee grounds), and wheat (wheat bran) were utilized to provide carbon sources for the production of a pectinase by B. amyloliquefaciens TKU050. B. amyloliquefaciens TKU050 expressed the highest pectinase productivity (0.76 U/mL) on 0.5% wheat bran-containing medium at 37°C for four days. A 58 kDa pectinase was purified from the four-day cultured medium fermented under optimized culture conditions with 7.24% of a recovery ratio and 0.51 U/mg of specific activity, respectively. The optimum temperature, optimum pH, thermal stability, and pH stability of the TKU050 pectinase were 50 °C, pH 6, <50 °C, and pH 6–9, respectively. The TKU050 pectinase was inhibited by sodium dodecyl sulfate and Cu²⁺. The reducing sugar obtained by hydrolyzing banana peel with TKU050 pectinase showed the growth-enhancing effect on the growth of four tested lactic acid bacteria.

The Role of Fruit by-Products as Bioactive Compounds for Intestinal Health

The fruit processing industry generates large amounts of wastes (pomace, seeds, peels) that causes negative environmental impact with considerable treatment expenses. Nevertheless, various studies demonstrated that these by-products are still rich in bioactive compounds, especially dietary fibres and phenolic compounds, thus leading to significant chemical, physical and biological properties. These characteristics make fruits by-products a good source for new supplements in food products having important effect on intestinal function. Thus, the aim of this review is to evaluate the different bioactive compounds isolated from fruit by-products and to analyse their application in various formulations for the food and nutraceutical industries. In consideration of the biological properties of these compounds, their role in the functioning and action on intestine and gut flora was discussed.

Deconstruction of banana peel for carbohydrate fractionation

The deconstruction of banana peel for carbohydrate recovery was performed by sequential treatment (acid, alkaline, and enzymatic). The pretreatment with citric acid promoted the extraction of pectin, resulting in a yield of 8%. In addition, xylose and XOS, 348.5 and 17.3 mg/g xylan, respectively, were also quantified in acidic liquor as a result of partial depolymerization of hemicellulose. The spent solid was pretreated with alkaline solution (NaOH or KOH) for delignification and release of residual carbohydrates from the hemicellulose. The yields of xylose and arabinose (225.2 and 174.0 mg/g hemicellulose) were approximately 40% higher in the pretreatment with KOH, while pretreatment with NaOH promoted higher delignification (67%), XOS yield (32.6 mg/g xylan), and preservation of cellulosic fraction. Finally, the spent alkaline solid, rich in cellulose (76%), was treated enzymatically to release glucose, reaching the final concentration of 28.2 g/L. The mass balance showed that through sequential treatment, 9.9 g of xylose, 0.5 g of XOS, and 8.2 g of glucose were obtained from 100 g of raw banana peels, representing 65.8% and 46.5% conversion of hemicellulose and cellulose, respectively. The study of the fractionation of carbohydrates in banana peel proved to be a useful tool for valorization, mainly of the hemicellulose fraction for the production of XOS and xylose with high value applications in the food industry.

Bioactives From Agri-Food Wastes: Present Insights and Future Challenges

Sustainable utilization of agri-food wastes and by-products for producing value-added products (for cosmetic, pharmaceutical or food industrial applications) provides an opportunity for earning additional income for the dependent industrial sector. Besides, effective valorisation of wastes/by-products can efficiently help in reducing environmental stress by decreasing unwarranted pollution. The major focus of this review is to provide comprehensive information on valorisation of agri-food wastes and by-products with focus laid on bioactive compounds and bioactivity. The review covers the bioactives identified from wastes and by-products of plants (fruits, exotic fruits, vegetables and seeds), animals (dairy and meat) and marine (fish, shellfish seaweeds) resources. Further, insights on the present status and future challenges of sustainably utilizing agri-food wastes/by-products for value addition will be highlighted.

Purification and characterization of a metalloprotease produced by the C8 isolate of Serratia marcescens using silkworm pupae or casein as a protein source

Serratiopeptidase, a metalloprotease produced by Serratia marcescens, is produced through a fermentation process using carbohydrates and proteins as carbon and nitrogen sources. However, some byproducts of the silk industry could be an alternative source for serratiopeptidase production. Therefore, the present work is focused on the purification and characterization of a serratiopeptidase produced from the C8 isolate of Serratia marcescens and obtained from a Colombian silkworm hybrid using casein or silkworm pupae. The protease was purified using ultrafiltration, anion-exchange, and size-exclusion chromatography. The purified enzyme showed a molecular weight of ~50 kDa with a purity above 96%, an isoelectric point of ~4.6, optimum pH and temperature of 6 and 50 °C, and stability at 4 °C for one month. The kinetic constants using azocasein as substrate were 0.63 mM (K_m), 2,016 μM/min (V_max), 41.41 s^-1 (K_cat), and 6.56 × 10⁷ M^-1 s^-1 (K_cat/K_m). Inhibition by 5 mM EDTA or 1,10-phenanthroline was recovered by adding Zn²⁺ at the same concentration. Mass spectrometry analysis indicated 94% homology with the sequence of serratiopeptidase produced by the E-15 strain. We purified and characterized a serratiopeptidase produced by the C8 isolate of S. marcescens in a culture medium based on a renewable source from the silk industry.