Use of response surface methodology to describe the effect of time and temperature on the production of decoloured, antioxidant and functional peptides from porcine haemoglobin by sub-critical water hydrolysis

A review on bioactive peptides derived from meat and by-products: Extraction methods, biological activities, applications and limitations

Meat and its by-products offer a rich source of bioactive compounds which have potential applications in both the food and pharmaceutical industries. In this review, we present several extraction methods and report the identification and properties of bioactive peptides. We also examine the challenges and limitations associated with their use in food applications. Enzymatic hydrolysis and fermentation using starts cultures are common methods for generating bioactive peptides from meat proteins. Additionally, natural gastrointestinal digestion can also produce bioactive peptides. However, emerging technologies like high hydrostatic pressure, subcritical extraction and pulsed electric fields can improve hydrolysis and increase the yield of bioactive peptides. Online bioinformatics applications have emerged as an established method for identifying potentially bioactive peptides. These tools reduce the cost and time required for traditional methods of research. Finally, incorporating bioactive peptides into diets for specific purposes such as supporting vulnerable populations like children and the elderly ensures safety and efficacy.

Antioxidant and Antimicrobial Peptides Derived from Food Proteins

Recently, the demand for food proteins in the market has increased due to a rise in degenerative illnesses that are associated with the excessive production of free radicals and the unwanted side effects of various drugs, for which researchers have suggested diets rich in bioactive compounds. Some of the functional compounds present in foods are antioxidant and antimicrobial peptides, which are used to produce foods that promote health and to reduce the consumption of antibiotics. These peptides have been obtained from various sources of proteins, such as foods and agri-food by-products, via enzymatic hydrolysis and microbial fermentation. Peptides with antioxidant properties exert effective metal ion (Fe2+/Cu2+) chelating activity and lipid peroxidation inhibition, which may lead to notably beneficial effects in promoting human health and food processing. Antimicrobial peptides are small oligo-peptides generally containing from 10 to 100 amino acids, with a net positive charge and an amphipathic structure; they are the most important components of the antibacterial defense of organisms at almost all levels of life-bacteria, fungi, plants, amphibians, insects, birds and mammals-and have been suggested as natural compounds that neutralize the toxicity of reactive oxygen species generated by antibiotics and the stress generated by various exogenous sources. This review discusses what antioxidant and antimicrobial peptides are, their source, production, some bioinformatics tools used for their obtainment, emerging technologies, and health benefits.

Protein Hydrolysis by Subcritical Water: A New Perspective on Obtaining Bioactive Peptides

The importance of bioactive peptides lies in their diverse applications in the pharmaceutical and food industries. In addition, they have been projected as allies in the control and prevention of certain diseases due to their associated antioxidant, antihypertensive, or hypoglycemic activities, just to mention a few. Obtaining these peptides has been performed traditionally by fermentation processes or enzymatic hydrolysis. In recent years, the use of supercritical fluid technology, specifically subcritical water (SW), has been positioned as an efficient and sustainable alternative to obtain peptides from various protein sources. This review presents and discusses updated research reports on the use of subcritical water to obtain bioactive peptides, its hydrolysis mechanism, and the experimental designs used for the study of effects from factors involved in the hydrolysis process. The aim was to promote obtaining peptides by green technology and to clarify perspectives that still need to be explored in the use of subcritical water in protein hydrolysis.

Production and processing of antioxidant bioactive peptides: A driving force for the functional food market

Recently, the demand for functional foods in the global market has increased rapidly due to the increasing occurrences of non-communicable diseases and technological advancement. Antioxidant peptides have been suggested as ingredients used to produce health-promoting foods. These peptides are encrypted from various food derived protein sources by chemical and enzymatic hydrolysis, and microbial fermentation. However, the industrial-scale production of antioxidant peptides is hampered by different problems such as high production cost, and low yield and bioactivity. Accordingly, novel processing technologies, such as high pressure, microwave and pulsed electric field, have been recently emerged to overcome the problems associated with the conventional hydrolysis methods. This particular review, therefore, discussed the current processing technologies used to produce antioxidant peptides. The review also suggested further perspectives that should be addressed in the future.

Removal of inorganic chemical species and organic matter from slaughterhouse wastewater via calcium acetate synthesized from eggshell

The physicochemical treatment (PT) of slaughterhouse wastewater (SWW) was investigated. In the first stage, calcium acetate (Ca(Ac)₂) was synthesized in five different ways: (1) acetic acid (HAc) and chicken eggshell (CaAc1), (2) lime (CaAc2), (3) a 1:1 eggshell and lime mixture (CaAc3), (4) a 1:2 eggshell and lime mixture (CaAc4), and (5) calcium oxide via the calcination of eggshell (CaAc5). The synthesized Ca(Ac)₂ samples were characterized by IR, SEM, XRD, and EDS. Subsequently, the samples were used to precipitate oxyanions and organic matter. The experiments were carried out at pH 4 and 12. For the treatment with CaAc1 at pH 4, an acid (HCl, H₂SO₄, or HAc) was also added. The best results for CaAc1 in acid media were attained with HCl, where removal efficiencies of 82.23% total suspended solids, 76% turbidity, 81.43% color, 53.86% Fe, 69.74% Cu, and 14.64% Na were observed. This treatment also removed ∼99% fecal and total coliforms, 26.49% COD, and 78.39% TOC. The experiments were also performed at pH 12 using CaAc1. These afforded removal efficiencies of 92.7% turbidity, 84.7% color, 40.5% phosphates (PO₄^3-), and 64.7% sulfates (SO₄^2-). In addition, this method removed metals, 35.37% COD and 99% fecal and total coliforms.

Preparation and Characterization of Antioxidant Peptides from Carrot Seed Protein

Carrot is a very popular vegetable and used for culinary and cosmetic purposes. Carrot seeds can be used for treatment of hangovers and stimulating menstruation. In the present study, the carrot seed protein (CSP) extracted from carrot seed (Daucus carota L.) was hydrolysed by four proteases (papain, trypsin, neutrase, and alcalase). Alcalase hydrolysate exhibited the strongest DPPH radical-scavenging activity (DRSA). The optimum hydrolysis condition for the antioxidant peptide production from CSP was obtained using response surface methodology (RSM). The optimum condition was as follows: hydrolysis time of 3.50 h, substrate concentration of 52.8 g/L, and protease dosage of 419.36 U/g, under which DRSA of 82.46% at 2 mg/mL was obtained. The carrot seed protein hydrolysates (CSPHs) were separated using size exclusion chromatography in order to obtain peptides with stronger antioxidant activity. The hydrolysates were fractionated into four peaks, and fractions F3 and F4 with smaller molecular weight showed stronger antioxidant activity. These findings indicated that the success of RSM in optimizing the hydrolysis conditions and the further work in separation of antioxidant peptides in CSPH is feasible. The CSPH exhibites good antioxidant properties and can be used as useful ingredient in foods.

Opportunities and perspectives for utilisation of co-products in the meat industry

Meat co-products are the non-meat components arising from meat processing/fabrication and are generated in large quantities on a daily basis. Co-products are considered as low added-value products, and in general it is difficult for industries to divert efforts into increasing their value. While many of these products can be edible those not used for human consumption or pet food is usually processed to be used as animal feed, fertilizer or fuel. However, to a large extent meat co-products are an excellent source of high nutritive value protein, minerals and vitamins and hence may be better diverted to contribute to alleviate the increasing global demand for protein. In this review the current uses, legislation and potential techniques for meat co-products processing are reviewed with the aim of showing a route to improve meat industry sustainability, profitability and better usage of available resources.

Harnessing the Potential of Blood Proteins as Functional Ingredients: A Review of the State of the Art in Blood Processing

Blood is generated in very large volumes as a by-product in slaughterhouses all around the world. On the one hand, blood generation presents a serious environmental issue because of its high pollutant capacity; however, on the other hand, blood has the potential to be collected and processed to generate high-added-value food ingredients based on its exceptional nutritive value and its excellent functional properties. In this paper, we review the current state of the art for blood processing, from collection to final recovery of protein isolates, the functional properties of blood, impact of processing on functional properties, and potential applications as food ingredients. Furthermore, future challenges are outlined for this underutilized and abundant product from the meat industry.