Innovations in value-addition of edible meat by-products

Evaluation of Drying Characteristics and Quality Attributes for Microwave Vacuum Drying of Pork Skin Crisps

As an important by-product of pork, pork skin can be processed into meat-based leisure food products to improve its utilization. In this study, microwave vacuum drying (MVD) technology was used to investigate the effects of microwave powers (600, 700, and 800 W) and processing duration on the drying characteristics and quality attributes of pork skin crisps (PSC). Five classical drying models were used to non-linearly fit the experimental data, and the Midilli et al. model was suitable for characterizing the MVD process of PSC. Before reaching a constant rate of drying, increasing microwave power and time can improve the brittleness and expansion ratio of PSC. In the constant rate drying stage, most of the free water in PSC was removed, showing the best brittleness and a stable expansion ratio. High power and long processing time can lead to serious lipid oxidation and change the flavor of PSC. Overall, the desired quality of PSC is recommended as 700 W for 6 min. This study can provide a reference for MVD application of meat-based by-product leisure foods.

Enzymatic hydrolysis of duck blood protein produces stable bioactive peptides: Pilot-scale production, identification, and stability during gastrointestinal and plasma digestion

This study addresses the valorization of duck blood, an underutilized protein-rich by-product from the poultry industry, into bioactive protein hydrolysates with antioxidant and ACE inhibitory properties. Raw and heat-treated duck blood were compared as substrates for enzymatic hydrolysis using Neutrase and Papain. Gel electrophoresis revealed that heat treatment reduced fibrinogen content, while FTIR analysis showed that heat treatment modified the protein structure, increasing β-sheet content from 21.13 % to 34.96 %. Heat-treated duck blood hydrolyzed by Neutrase exhibited superior hydrolysis (9.53 %) and protein recovery (60.28 %) compared to raw blood. Pilot-scale production (1000 L) enhanced hydrolysate yield and maintained bioactive properties. LC-MS/MS analysis identified five novel bioactive peptides derived from the hydrolysate's 4-h simulated gastrointestinal (GI) digestion, with WMHVR demonstrating the highest antioxidant and ACE inhibitory activities. Molecular docking simulations revealed that WMHVR competitively inhibits ACE by binding to the S1, S2, and S' pockets through van der Waals and hydrogen bonding interactions. The GI-hydrolysate and identified peptides maintained bioactivity during simulated GI and blood plasma digestion, with ACE inhibition increasing over time. This research transforms food industry waste into functional protein hydrolysates, offering applications in nutraceuticals and functional foods while promoting sustainable practices through waste protein valorization.

Unexplored Opportunities of Utilizing Food Waste in Food Product Development for Cardiovascular Health

PURPOSE OF REVIEW

Global food production leads to substantial amounts of agricultural and food waste that contribute to climate change and hinder international efforts to end food insecurity and poverty. Food waste is a rich source of vitamins, minerals, fibers, phenolic compounds, lipids, and bioactive peptides. These compounds can be used to create food products that help reduce heart disease risk and promote sustainability. This review examines the potential cardiovascular benefits of nutrients found in different food waste categories (such as fruits and vegetables, cereal, dairy, meat and poultry, and seafood), focusing on animal and clinical evidence, and giving examples of functional food products in each category.

RECENT FINDINGS

Current evidence suggests that consuming fruit and vegetable pomace, cereal bran, and whey protein may lower the risk of cardiovascular disease, particularly in individuals who are at risk. This is due to improved lipid profile, reduced blood pressure and increased flow-mediated dilation, enhanced glucose and insulin regulation, decreased inflammation, as well as reduced platelet aggregation and improved endothelial function. However, the intervention studies are limited, including a low number of participants and of short duration. Food waste has great potential to be utilized as cardioprotective products. Longer-term intervention studies are necessary to substantiate the health claims of food by-products. Technological advances are needed to improve the stability and bioavailability of bioactive compounds. Implementing safety assessments and regulatory frameworks for functional food derived from food waste is crucial. This is essential for maximizing the potential of food waste, reducing carbon footprint, and improving human health.

Evaluation of the Sensory Quality and Shelf Life of a Bioactive Essence Rich in Monounsaturated Fatty Acids and Antioxidants, Obtained from Eco-Sustainable Iberian Ham

Food sustainability through traditional food production and the reuse of food by-products is one of the characteristics most valued by consumers. The production of Iberian ham is linked to the vaporization and sustainability of the dehesa and the conservation and maintenance of the rural environment, but there are some by-products that are not destined for direct consumption. In this context, previous studies have used trimmed fat to obtain a bioactive essence rich in antioxidants and monounsaturated fatty acids. Furthermore, it is important to keep in mind that the consumer's decision is influenced by the nutritional/health and sensory characteristics of the product and its shelf life. The objective of the present study was to evaluate consumer acceptance and/or preference of different essences obtained from the trimmed fat of sliced Iberian ham and to determine the microbiological and physicochemical stability of the selected sustainable essence over time. The results showed that this essence is generally accepted by consumers and is microbiologically stable over time.

The Role of Lactic Acid Bacteria in Meat Products, Not Just as Starter Cultures

Lactic acid bacteria (LABs) are microorganisms of significant scientific and industrial importance and have great potential for application in meat and meat products. This comprehensive review addresses the main characteristics of LABs, their nutritional, functional, and technological benefits, and especially their importance not only as starter cultures. LABs produce several metabolites during their fermentation process, which include bioactive compounds, such as peptides with antimicrobial, antidiabetic, antihypertensive, and immunomodulatory properties. These metabolites present several benefits as health promoters but are also important from a technological point of view. For example, bacteriocins, organic acids, and other compounds are of great importance, whether from a sensory or product quality or a safety point of view. With the production of GABA, exopolysaccharides, antioxidants, and vitamins are beneficial metabolites that influence safety, technological processes, and even health-promoting consumer benefits. Despite the benefits, this review also highlights that some LABs may present virulence properties, requiring critical evaluation for using specific strains in food formulations. Overall, this review hopes to contribute to the scientific literature by increasing knowledge of the various benefits of LABs in meat and meat products.

Quality Evaluation of Chicken Liver Pâté Affected by Algal Hydrocolloids Addition: A Textural and Rheological Approach

Hydrocolloids are used in spreadable meat or poultry products to improve consistency, emulsion stability and water retention, resulting in products with desired functional and organoleptic properties. The scope of the work was to evaluate the addition of three divergent algal hydrocolloids (κ-carrageenan, ι-carrageenan, furcellaran) at four different concentrations (0.25, 0.50, 0.75, and 1.00% w/w) on the physicochemical, textural, rheological and organoleptic properties of model chicken liver pâté (CLP) samples. Overall, the highest hardness and viscoelastic moduli values of the CLP samples were reported when κ-carrageenan and furcellaran were utilized at a concentration of 0.75% w/w (p < 0.05). Furthermore, increasing the concentrations of the utilized hydrocolloids led to increase in the viscoelastic moduli and hardness values of CLP. Compared to the control sample, an increase in spreadability was reported in the CLP samples with the addition of hydrocolloids. Finally, the use of algal hydrocolloids proved to be an effective way to modify the techno-functional properties of CLP.

Valorization of Pig Brains for Prime Quality Oil: A Comparative Evaluation of Organic-Solvent-Based and Solvent-Free Extractions

Pig processing industries have produced large quantities of by-products, which have either been discarded or used to make low-value products. This study aimed to provide recommendations for manufacturing edible oil from pig brains, thereby increasing the value of pork by-products. The experiment compared non-solvent extraction methods, specifically wet rendering and aqueous saline, to a standard solvent extraction method, the Bligh and Dyer method, for extracting oil from pig brains. The yield, color, fatty acid profile, a number of lipid classes, and lipid stability against lipolysis and oxidation of the pig brain oil were comprehensively compared, and the results revealed that these parameters varied depending on the extraction method. The wet rendering process provided the highest extracted oil yield (~13%), followed by the Bligh and Dyer method (~7%) and the aqueous saline method (~2.5%). The Bligh and Dyer method and wet rendering techniques produced a translucent yellow oil; however, an opaque light-brown-red oil was found in the aqueous saline method. The Bligh and Dyer method yielded the oil with the highest phospholipid, cholesterol, carotenoid, tocopherol, and free fatty acid contents (p < 0.05). Although the Bligh and Dyer method recovered the most unsaturated fatty acids, it also recovered more trans-fatty acids. Aqueous saline and wet rendering procedures yielded oil with low FFA levels (<1 g/100 g). The PV of the oil extracted using all methods was <1 meq/kg; however, the Bligh and Dyer method had a significant TBARS content (7.85 mg MDA equivalent/kg) compared to aqueous saline (1.75 mg MDA equivalent/kg) and wet rendering (1.14 mg MDA equivalent/kg) (p < 0.05). FTIR spectra of the pig brain oil revealed the presence of multiple components in varying quantities, as determined by chemical analysis experiments. Given the higher yield and lipid stability and the lower cholesterol and trans-fatty acid content, wet rendering can be regarded as a simple and environmentally friendly method for safely extracting quality edible oil from pig brains, which may play an important role in obtaining financial benefits, nutrition, the zero-waste approach, and increasing the utilization of by-products in the meat industry.

Effect of Bile Acids Supplementation in Fatty Liver Hemorrhagic Syndrome, Production Performance, Physiological and Quality Characteristics of Laying Hen Eggs

This study aimed to investigate the effects of bile acids (BAs) supplementation on fatty liver hemorrhagic syndrome (FLHS), production performance, and physiological and quality characteristics of laying hen eggs. Sixty Sanhuang laying hens, aged 28 weeks, were randomly allocated to six dietary treatments over a 4-week period, including the control (CON) group (feeding basal diet), the high-fat diet (HFD)-treated group (basal diet containing 10% soybean oil), and HFD supplemented with 0.01% and 0.02% of chenodeoxycholic acid (CDCA) or hyodeoxycholic acid (HDCA) groups. Production performance, egg quality, liver morphology, serum biochemical indexes, antioxidant capacity, proinflammatory cytokines, and intestinal microbiota were evaluated. The average body weight in 0.01% CDCA was larger than in the HFD group (p < 0.05). Eggshell Thickness in the CON group was greater than in the HFD, 0.01% CDCA, and HDCA groups (p < 0.05). Albumen height in the 0.02% HDCA group was higher than the HFD group (p < 0.05). Eggshell weight in the HFD group was less than the CON group (p < 0.05). Haugh unit (HU) in the HDCA group was larger than the HFD group (p < 0.05). Albumen weight in the 0.02% HDCA group was greater than the CON and HFD groups (p < 0.05). In the HFD group, the levels of triglyceride (TG), total cholesterol (TC), and low-density lipo-protein cholesterol (LDL-C) were surpassing the other groups (p < 0.05). The levels of catalase (CAT) and total superoxide dismutase (T-SOD) in the HFD group was smaller than the other groups (p < 0.05). The level of malondialdehyde (MDA) in the HFD group was higher than in the other groups (p < 0.05). Tumor necrosis factor-α (TNF-α) levels were larger in the HFD group than in the other groups (p < 0.05). The 16S rRNA sequencing analysis indicated significant variations in the relative abundance of specific bacterial populations among the different treatment groups. The treatment and CON groups exhibited a higher presence of bacteria that inhibit host energy absorption or promote intestinal health such as Firmicutes, Bacteroidetes, and Ruminococcus, whereas the HFD group showed an increased prevalence of potentially pathogenic or deleterious bacteria, such as Desulfovibrio spp. In conclusion, the supplementation of BAs in poultry feed has been demonstrated to effectively mitigate the detrimental effects of FLHS in laying hens. This intervention regulates lipid metabolism, bolsters antioxidant defenses, reduces inflammation, and modulates the gut microbiota, offering a novel perspective on the application of BAs in the poultry industry.

Edible Offal as a Valuable Source of Nutrients in the Diet-A Review

The global increase in demand for meat leads to substantial quantities of by-products, including edible offal from both wild and domesticated animals raised for diversified consumption products within an agricultural framework. Information on the nutritional value of offal is scattered and limited. This review aims to synthesize scientific publications on the potential of offal as a source of nutrients and bioactive substances in human diets. The literature review included publications available in ISI Web of Science and Google Scholar published between 2014 and 2024. Findings indicate that edible offal is characterized by a nutrient concentration often surpassing that found in skeletal muscle. This review discusses the yield of edible offal and explores factors influencing human consumption. Selected factors affecting the nutritional value of offal of various animals and the importance of individual nutrients in ensuring the proper functioning of the human body were analyzed. The optimal use of offal in processing and catering can significantly benefit aspects of human life, including diet quality, food security, and conservation of natural resources.

Improving Human Diets and Welfare through Using Herbivore-Based Foods: 1. Human and Animal Perspectives

Human health and diet are closely linked. The diversity of diets consumed by humans is remarkable, and most often incorporates both animal and plant-based foods. However, there has been a recent call for a reduced intake of animal-based foods due to concerns associated with human health in developed countries and perceived impacts on the environment. Yet, evidence for the superior nutritional quality of animal-sourced food such as meat, milk, and eggs, compared with plant-based foods, indicates that consumption of animal-sourced food should and will continue. This being the case, the aim here is to examine issues associated with animal-sourced foods in terms of both the quantification and mitigation of unintended consequences associated with environment, animal health, and herd management. Therefore, we examined the role of animal proteins in human societies with reference to the UN-FAO issues associated with animal-sourced foods. The emphasis is on dominant grazed pastoral-based systems, as used in New Zealand and Ireland, both with temperate moist climates and a similar reliance on global markets for generating net wealth from pastoral agricultural products. In conclusion, animal-sourced foods are shown to be an important part of the human diet. Production systems can result in unintended consequences associated with environment, animal health, and herd management, and there are technologies and systems to provide solutions to these that are available or under refinement.

Functional recovery following traumatic brain injury in rats is enhanced by oral supplementation with bovine thymus extract

Traumatic brain injury (TBI) is one of the leading causes of death worldwide. There are currently no effective treatments for TBI, and trauma survivors suffer from a variety of long-lasting health consequences. With nutritional support recently emerging as a vital step in improving TBI patients' outcomes, we sought to evaluate the potential therapeutic benefits of nutritional supplements derived from bovine thymus gland, which can deliver a variety of nutrients and bioactive molecules. In a rat model of controlled cortical impact (CCI), we determined that animals supplemented with a nuclear fraction of bovine thymus (TNF) display greatly improved performance on beam balance and spatial memory tests following CCI. Using RNA-Seq, we identified an array of signaling pathways that are modulated by TNF supplementation in rat hippocampus, including those involved in the process of autophagy. We further show that bovine thymus-derived extracts contain antigens found in neural tissues and that supplementation of rats with thymus extracts induces production of serum IgG antibodies against neuronal and glial antigens, which may explain the enhanced animal recovery following CCI through possible oral tolerance mechanism. Collectively, our data demonstrate, for the first time, the potency of a nutritional supplement containing nuclear fraction of bovine thymus in enhancing the functional recovery from TBI.

Applications and safety aspects of bioactives obtained from by-products/wastes

Due to the negative impacts of food loss and food waste on the environment, economy, and social contexts, it is a necessity to take action in order to reduce these wastes from post-harvest to distribution. In addition to waste reduction, bioactives obtained from by-products or wastes can be utilized by new end-users by considering the safety aspects. It has been reported that physical, biological, and chemical safety features of raw materials, instruments, environment, and processing methods should be assessed before and during valorization. It has also been indicated that meat by-products/wastes including collagen, gelatin, polysaccharides, proteins, amino acids, lipids, enzymes and chitosan; dairy by-products/wastes including whey products, buttermilk and ghee residue; fruit and vegetable by-products/wastes such as pomace, leaves, skins, seeds, stems, seed oils, gums, fiber, polyphenols, starch, cellulose, galactomannan, pectin; cereal by-products/wastes like vitamins, dietary fibers, fats, proteins, starch, husk, and trub have been utilized as animal feed, food supplements, edible coating, bio-based active packaging systems, emulsifiers, water binders, gelling, stabilizing, foaming or whipping agents. This chapter will explain the safety aspects of bioactives obtained from various by-products/wastes. Additionally, applications of bioactives obtained from by-products/wastes have been included in detail by emphasizing the source, form of bioactive compound as well as the effect of said bioactive compound.

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.

Plasmalogen Profiling in Porcine Brain Tissues by LC-MS/MS

Plasmalogen, a functional glycerophospholipid, is known for its beneficial nutritional effects, such as anti-oxidation and anti-inflammation. As the porcine brain is a plasmalogen-rich resource, this study aimed to explore its potential for plasmalogen-based health food product development, with special attention on whether and how the industrial production processes influence the plasmalogen content and composition. In the present work, plasmalogens from different porcine brain products were investigated using liquid chromatography-tandem mass spectrometry. The results indicated that all the porcine brain products showed abundant total plasmalogens, of which more than 95% were ethanolamine plasmalogen species. Acetone precipitation, ethanol extraction, and drying did not significantly affect the plasmalogen content, whereas repeated freeze-thaw cycles in the production process led to noticeable loss. The chemometric investigation suggested that raw products and glycerophospholipid products exhibited different profiles; furthermore, the concentration step seemed to impact the plasmalogen composition. The nutritional assessment revealed that porcine brain products showed favorable values of multiple indexes, including PUFA/SFA ratio, n-6/n-3 ratio, thrombogenicity index, and unsaturation index, suggesting a health-beneficial value. The current study not only shows the feasibility of producing porcine brain-derived plasmalogens, but also provides possible strategies for developing and quality-controlling dietary plasmalogen supplements and healthcare products.

Potential of Human Hemoglobin as a Source of Bioactive Peptides: Comparative Study of Enzymatic Hydrolysis with Bovine Hemoglobin and the Production of Active Peptide α137-141

Cruor, the main component responsible for the red color of mammalian blood, contains 90% haemoglobin, a protein considered to be a rich source of bioactive peptides. The aim of the present study is to assess the potential of human hemoglobin as a source of bioactive peptides, compared with bovine hemoglobin, which has been extensively studied in recent years. More specifically, the study focused on the α137-141 fragment of bovine haemoglobin (TSKYR), a small (653 Da) hydrophilic antimicrobial peptide. In this work, the potential of human hemoglobin to contain bioactive peptides was first investigated in silico in comparison with bovine hemoglobin-derived peptides using bioinformatics tools. The blast results showed a high identity, 88% and 85% respectively, indicating a high similarity between the α and β chains. Peptide Cutter software was used to predict cleavage sites during peptide hydrolysis, revealing major conservation in the number and location of cleavage sites between the two species, while highlighting some differences. Some peptides were conserved, notably our target peptide (TSKYR), while others were specific to each species. Secondly, the two types of hemoglobin were subjected to similar enzymatic hydrolysis conditions (23 °C, pH 3.5), which showed that the hydrolysis of human hemoglobin followed the same reaction mechanism as the hydrolysis of bovine hemoglobin, the 'zipper' mechanism. Concerning the peptide of interest, α137-141, the RP-UPLC analyses showed that its identification was not affected by the increase in the initial substrate concentration. Its production was rapid, with more than 60% of the total α137-141 peptide production achieved in just 30 min of hydrolysis, reaching peak production at 3 h. Furthermore, increasing the substrate concentration from 1% to 10% (w/v) resulted in a proportional increase in α137-141 production, with a maximum concentration reaching 687.98 ± 75.77 mg·L-1, approximately ten-fold higher than that obtained with a 1% (w/v) concentration. Finally, the results of the UPLC-MS/MS analysis revealed the identification of 217 unique peptides in bovine hemoglobin hydrolysate and 189 unique peptides in human hemoglobin hydrolysate. Of these, 57 peptides were strictly common to both species. This revealed the presence of several bioactive peptides in both cattle and humans. Although some had been known previously, new bioactive peptides were discovered in human hemoglobin, such as four antibacterial peptides (α37-46 PTTKTYFPHF, α36-45 FPTTKTYFPH, α137-141 TSKYR, and α133-141 STVLTSKYR), three opioid peptides (α137-141 TSKYR,β31-40 LVVYPWTQRF,β32-40, VVYPWTQRF), an ACE inhibitor (β129-135 KVVAGVA), an anticancer agent (β33-39 VVYPWTQ), and an antioxidant (α137-141 TSKYR). To the best of our knowledge, these peptides have never been found in human hemoglobin before.

Developing a procedure to extract chenodeoxycholic acid and synthesize ursodeoxycholic acid from pig by-products

This study was conducted to develop simple methods for the extraction of chenodeoxycholic acid (CDCA) and synthesis of ursodeoxycholic acid (UDCA) from pig by-products. The enzymatic method, which uses bile salt hydrolase (BSH) enzymes to extract CDCA, was found to be more efficient than the chemical method. The chemical method, which uses pig by-products, resulted in UDCA amounts of 6.05 mg, 0.51 mg, 3.04 mg, and 1.26 mg in 100 g of the liver, stomach, small intestine, and large intestine, respectively. The amounts of UDCA synthesized/100 g through the chemical and enzymatic methods required to extract CDCA were 3.48 g and 2.22 g, respectively. The procedure developed in this study was simplified by three stages compared to the conventional chemical method of extracting CDCA. Moreover, this study provides a technique that improves the utilization of pig by-products.

Investigation Tracing the Origin of Tan Sheep Visceral Tissues through Mineral Elements

The traceability of quality mineral fingerprints in the viscera of Tan sheep from northwest China was studied. Twenty-five mineral elements in the heart and liver samples of Tan sheep were determined using an inductively coupled plasma mass spectrometer (ICP-MS), and the characteristics of the mineral elements in the visceral tissues of the Tan sheep were further analyzed in combination with a principal component analysis (PCA), hierarchical cluster analysis (HCA), and linear discriminant analysis (LDA) to establish a discriminant model and verify it. The results show that 11 elements (¹³⁷Ba, ⁴³Ca, ⁶³Cu, ⁵⁶Fe, ³⁹K, ³¹P, ⁶⁰Ni, ⁷⁸Se, ¹¹⁸Sn, ¹²⁵Te, and ⁶⁶Zn) in the Tan sheep heart samples had significant differences among different regions (p < 0.05), and the results of the LDA show that the accuracy rate of the return-generation examination was 85.70%, and the accuracy rate of the hand-over-fork examination was 87.50%; 10 elements (¹¹¹Cd, ⁵⁹Co, ⁵²Cr, ⁵⁶Fe, ³⁹K, ⁵⁵Mn, ⁹⁵Mo, ²³Na, ¹²¹Sb, and ⁷⁸Se) in the Tan sheep liver samples had significant differences among different regions (p < 0.05), and the results of the LDA showed that the accuracy rate of the return-generation examination was 96.30%, and the accuracy rate of the hand-over-fork examination was 86.25%. This indicates that the multi-element analysis has potential for determining the origin of Tan sheep viscera in certain regions.

Meat Consumption, Sustainability and Alternatives: An Overview of Motives and Barriers

Meat and meat products are important sources of protein in the human diet. However, their consumption or excessive consumption has been questioned as this has been related to sustainability and health issues. Due to this, alternatives to conventional meat consumption, such as meat produced more sustainably or meat alternatives, have been considered. The aim of the present work is to gain insight into the meat consumption of different countries, the motives for and barriers to this consumption, as well as into the consumption of more sustainably produced meat with particular focus on organic meat and meat alternatives. Information on meat consumption has been obtained using FAOSTAT data and maps have been constructed using SAS software. Results showed that, in general, albeit with variations between and within countries, there is a tendency to decrease red meat consumption and increase poultry consumption, while for pork consumption the tendency is less clear. Motives and barriers for meat and meat alternative consumption have been reviewed and it is possible to see that these are very variable and that they, in addition to the intrinsic and extrinsic characteristics of the meat, are also related to consumers' attitudes and beliefs. Thus, it is important to inform consumers in a truthful and reliable way in order to allow them to make well-founded decisions regarding the consumption of these products.

Role of Enzymatic Reactions in Meat Processing and Use of Emerging Technologies for Process Intensification

Meat processing involves different transformations in the animal muscle after slaughtering, which results in changes in tenderness, aroma and colour, determining the quality of the final meat product. Enzymatic glycolysis, proteolysis and lipolysis play a key role in the conversion of muscle into meat. The accurate control of enzymatic reactions in meat muscle is complicated due to the numerous influential factors, as well as its low reaction rate. Moreover, exogenous enzymes are also used in the meat industry to produce restructured products (transglutaminase), to obtain bioactive peptides (peptides with antioxidant, antihypertensive and gastrointestinal activity) and to promote meat tenderization (papain, bromelain, ficin, zingibain, cucumisin and actinidin). Emerging technologies, such as ultrasound (US), pulsed electric fields (PEF), moderate electric fields (MEF), high-pressure processing (HPP) or supercritical CO₂ (SC-CO₂), have been used to intensify enzymatic reactions in different food applications. This review aims to provide an overview of the enzymatic reactions taking place during the processing of meat products, how they could be intensified by using emerging technologies and envisage potential applications.

Unlocking the bioactivity of meat proteins: Comparison of meat and meat hydrolysate via simulated gastrointestinal digestion

Understanding the functional attributes of meat proteins is crucial for determining their nutritional benefits. Depending on the form in which meat proteins are available, the digestive process can release peptides which are valuable for nutrition and may also possess bioactive properties, affecting physiology. Liquid chromatography - mass spectrometry (LC-MS) was used to quantitatively compare the molecular peptide features (representing non-redundant peptides), during the different stages of a simulated gastrointestinal digestion process of a minimally processed powdered meat and its enzymatically produced hydrolysate. Results from a principal component analysis (PCA) indicated that the hydrolysate did not undergo extensive additional digestion whereas the powdered meat was digested both at the gastric and in the intestinal phases. Bioactive peptide sequence prediction identified the meat hydrolysate but not the meat powder as the only source of exact and partial bioactive matches in the angiotensin-I converting enzyme and dipeptidyl peptidase IV inhibition categories. Also, a higher source of cryptides (encrypted bioactive peptides), indicated that meat hydrolysates are potentially a better substrate for the release of these enzyme inhibitory peptides. These observations thus suggest that pre-digestion of a complex food matrix such as meat, may enhance its bioavailability following oral consumption early in the digestion process. SIGNIFICANCE: This work highlights enzymatic hydrolysis of meat proteins prior to ingestion allows for potentially higher bioavailability of bioactive peptides that inhibit angiotensin-I converting enzyme and dipeptidyl peptidase IV, thus possibly aiding high blood pressure and type 2 diabetes management.

Antioxidant and angiotensin-I-converting enzyme (ACE-I) inhibitory activities of protein hydrolysates derived from water buffalo (Bubalus bubalis) liver

In the current study, we attempted to use ginger as a novel and natural source of protease in comparison with other commercially available enzymes to extract and characterize antioxidant and antihypertensive hydrolysates from water buffalo liver, a protein rich offal. Hydrolysis of protein extracts from buffalo liver using proteinase-K, pronase-E and ginger protease significantly increased the %degree of hydrolysis (18.5-55%) and generated low-molecular weight peptides evident from SDS-PAGE. Enzyme treated hydrolysates exhibited higher (p < 0.05) DPPH radical scavenging activity (43.7-82.4%) and angiotensin-I-converting enzyme (ACE-I) inhibitory activity (46.9-50.1%) relative to control. Mass spectrometric analysis (MALDI-TOF MS) of selected gel-filtered fractions identified few important peptides derived from nuclear ribonucleoprotein, pyruvate kinase and phosphoglycerate kinase that possess strong antioxidant activity. Present findings indicate the efficacy of partially purified ginger as a novel source of protease in generating protein hydrolysates from water buffalo liver with significant antioxidant and antihypertensive activity in vitro. We successfully demonstrated the recovery of functional bioactive peptides from water buffalo liver which presents a potential opportunity for the meat industries to economically use this important byproduct.

Valuation of Goat and Sheep By-Products: Challenges and Opportunities for Their Use

Goat and sheep meat production is a challenge for the meat industry as well as for environmental management. Yet within cultures, certain by-products, such as liver, the lungs, heart, brain, spleen, blood, tail and ears, are traditionally used in the production of typical dishes for regional or local cuisine. These by-products are a rich source of lipids, proteins, essential amino acids, B-complex vitamins, and minerals. They can be effectively exploited for higher (value-added) applications, including functional foods or feed ingredients, food supplements, enzymes and other chemical products such as hydrolyzed proteins and flavorings. This review article gathers data on: (i) the production of by-products obtained from slaughter and available for processing, and (ii) potential strategies for using and applying these by-products in obtaining new value-added ingredients. Other than proteins, the review discusses other macromolecules and possible uses of these by-products in culinary dishes, as hydrolyzed enzymes, and as food additives. Even though these by-products undoubtedly present themselves as rich in nutrients, there remains an unfortunate lack of documented information on the potential use of these by-products for their bioactive components, peptides that have various biological and technological properties, and the use of hydrolyzed versions of these by-products as precursors for the production of flavorings.

Comparison of techno-functional and sensory properties of sponge cakes made with egg powder and different quality of powdered blood products for substituting egg allergen and developing functional food

Animal blood is a valuable resource, which is usually not utilized in a value-added way by the industry like other animal by-products, even though it has plenty of benefits in terms of sustainability and human health, particularly against iron deficiency anemia. Animal blood is perfectly suitable for providing special functions, which are necessary for functional foods, and improving techno-functional properties based on the previous reports published in the literature. In this paper, egg powder was substituted by powdered animal blood products (whole blood powder, blood plasma powder, and hemoglobin powder) in sponge cake. Techno-functional and sensory properties (texture by texture profile analysis and three-point breaking test, water activity, dry matter content, and color) were instrumentally measured and then a sensory evaluation was carried out by unskilled panelists. Quality characteristics (texture, color, and dry matter content) were daily measured on the day of baking and then every 24 h for 3 additional days because freshly baked cakes are usually consumed within 3 days. Based on the results, powdered blood products are suitable for substituting the egg powder in sponge cakes and developing functional foods. Blood powders can increase the hardness, chewiness, and breaking force of cakes, giving them the ability to be stuffed with more fillings and molded into special shapes without compromising on the sensory characteristics. They can also increase the intensity of the cocoa flavor, which results in a richer, darker color without deceiving the consumers.

Physicochemical and Techno-Functional Properties of Dried and Defatted Porcine Liver

Porcine liver has a high nutritional value and is rich in proteins, minerals, and vitamins, making it an interesting co-product to alleviate the growing global demand for protein. The objective of this study was to analyze how the drying and defatting processes of porcine liver affect the physicochemical and techno-functional properties of its proteins. Two drying temperatures (40 and 70 °C) were studied, and dried samples were defatted using organic solvents. The drying process turned out to be an effective method for the stabilization of the protein fraction; however, when the drying temperature was high (70 °C), greater protein degradation was found compared to drying at a moderate temperature (40 °C). Regarding the defatting stage, it contributed to an improvement in certain techno-functional properties of the liver proteins, such as the foaming capacity (the average of the dried and defatted samples was 397% higher than the dried samples), with the degree of foaming stability in the liver dried at 40 °C and defatted being the highest (13.76 min). Moreover, the emulsifying capacity of the different treatments was not found to vary significantly (p > 0.05). Therefore, the conditions of the drying and defatting processes conducted prior to the extraction of liver proteins must be properly adjusted to maximize the stability, quality, and techno-functional properties of the proteins.

Machine-learning assisted modelling of multiple elements for authenticating edible animal blood food

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The critical elements for identifying species of the animal blood food were selected.

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Elemental fingerprint coupled with ELM were proposed for species identification of the animal blood food.

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The optimal ELM model for identifying the species of the animal blood food was constructed.

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The absolute and relative content of 25 elements in animal blood food were reported for the first time.

Elemental fingerprint coupled with machine learning modelling was proposed for species authentication of the edible animal blood gel (EABG). A total of 25 elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS) in 150 EABG samples prepared from five species of animals, namely duck, chicken, bovine, pig, and sheep. Extreme learning machine (ELM) models were constructed and optimized. Principal component analysis and Fisher linear discriminant analysis were comparatively utilized for dimension reduction of the crucial input elements selected via stepwise discriminant analysis and one-way ANOVA. The optimal ELM model was obtained with the crucial elements selected by one-way ANOVA from the relative content of the measured elements, which afforded accuracies of 98.0% and 96.0% for the training and test set, respectively. All findings suggest that elemental fingerprint accompanied by ELM have great potential in authenticating the edible animal blood food.

Detection of food fraud of meat products from the different brands by application of histological methods

In Sohag City, 400 samples were collected from different food markets of different meat products from two companies with high and low prices (e.g., minced meat, kofta sausage, beef burger, and luncheon meat) for determining food fraud. Light, fluorescence, and scanning electron microscopy (SEM) were used to examine the samples. "Special histochemical stains" permit the microscopic examination of different cell types, structures, and/or microorganisms. Histological examination revealed variant tissue types, besides skeletal muscles. Nuchal ligaments, bones, hyaline cartilages, white fibrocartilages, large and medium arteries, cardiac muscles, tendons, and collagenous connective tissues comprised the capsule of a parenchymatous organ. Additionally, a crystal of food additives was recognized using light microscopy and SEM. SEM allows the visualization of bacterial contamination. Using different microscopic anatomy techniques is an efficient methodology for qualitative evaluations of various meat products. No difference in quality was observed between low- and high-priced meat products.

A comprehensive techno-economic analysis of income-generating sources on the conversion of real sheep slaughterhouse waste stream into valorized by-products

The present analysis was conducted as the first research to assess the techno-economic viability of the value-added by-products (struvite, blood meal, bone meal, and raw sheepskin) from a medium-scale sheep slaughterhouse facility with a slaughtering capacity of 300 sheep per day. For this aim, a comparative technical and economic feasibility analysis was performed to assess the synergistic use of slaughterhouse-oriented rendering wastes and struvite recovery from real sheep abattoir effluent within the framework of detailed cost breakdown, break-even point, and payback period analyses. The experimental findings clearly showed that under the optimal conditions (chemical combination of MgCl₂.6H₂O + NaH₂PO₄.2H₂O, a molar ratio of Mg²⁺:NH₄⁺-N:PO₄^3--P = 1.2:1:1, a reaction pH of 9.0, an initial ammonium concentration of 240 mg NH₄⁺-N/L, and a reaction time of 15 min), struvite precipitation could effectively remove about 73%, 64%, 59%, and 82% of NH₄⁺-N, TCOD, SCOD, and color, respectively, from the real sheep slaughterhouse waste stream. Based on various up-to-date techno-economic items considered within the break-even point analysis, the sheep slaughterhouse facility was estimated to achieve the targeted net income (€100/day) for any selling prices of €1041.30/ton, €640.05/ton, €263.72/ton, and €1.012/hide, respectively, for struvite, blood meal, bone meal, and raw sheepskin. Steel construction and chemicals were determined as the most costly components for CAPEX (capital expenditures) and OPEX (operating expenditures), respectively, and selling prices of bone meal and raw sheepskin were found to be the most critical income items on the profitability of the slaughterhouse facility. Co-monetary assessment of the struvite process and valorized compounds corroborated the economic viability of the proposed project with the payback periods of about 6.3 and 5.5 years, respectively, for the current market and the profit-oriented conditions without subsidy. The findings of this feasibility analysis, as the first of its own, could be used as guideline for simplifying the decision-making with regards to the feasibility of similar facilities and commercialization of profitable by-products.

Analysis of the Food Loss and Waste Valorisation of Animal By-Products from the Retail Sector

The meat industry generates a large amount of animal by-products not only derived from the slaughter process but also due to the losses and waste of meat products along the supply chain, contributing to the world’s food loss and waste problem. Yearly, 1.7 Mt of meat in the European retail sector and 20% of meat for consumption is wasted in this sector of the supply chain. Therefore, the aim of this paper was to find and evaluate alternatives for the valorisation of agri-food residues, more specifically the meat waste from the food retail sector, through a technological perspective. Thus, we delve into the industrial processes already implemented and the emerging procedures that use muscle, bones and fats by-products from poultry, cattle and pork as the main raw materials in order to identify and characterise them. The results indicate that in addition to the current destinations—landfill, incineration and the rendering process—these animal by-products can be incorporated in the production of biodiesel, food formulations, pharmaceuticals, fertilisers and biogas through an industrial symbiosis approach. Consequently, the several valorisation processes and procedures identified not only suggest an increase in concern about the impacts of the disposal of these materials, but also highlight the potential associated with the use of animal by-products as raw material to obtain added-value products.

Recovery of Functional Proteins from Pig Brain Using pH-Shift Processes

The goal of this work is to explore if pH-shift processing could be used as a cold refinery technique to manufacture pig brain protein isolate (PI). Pig brain protein had the highest solubility at pH 2 (acid method) and pH 12 (alkaline method). As the protein solution’s zeta-potential was near 0 with the lowest solubility, pH 5.0 was chosen as the precipitation pH. Alkaline process produced a 32% dry matter yield with phospholipid content of 35 mg/100 g. The alkaline-made PI was better at forming soft gels and had good emulsifying and foaming capabilities. Although the acid-made PI included less residual lipid and total haem protein and was whiter in colour, it could not be gelled. Acid-made PI was more prone to lipid oxidation with a poorer ability to function as an emulsifier and foaming agent. Thus, functional proteins from pig brain may be isolated using the alkaline pH-shift technique.

Exploring the prospects of the fifth quarter in the 21st century

A variable proportion of slaughtered livestock, generally referred to as the fifth quarter, is not part of the edible dressed meat and regarded as animal byproduct. In order for the fifth quarter to play a significant role in the current effort toward a circular bio-based economy, it has to successfully support food security, social inclusivity, environmental sustainability, and a viable economy. The high volume of these low-value streams and their nutrient-dense nature can facilitate their position as a very important candidate to explore within the context of a circular bio-based economy to achieve some of the United Nations Sustainable Development Goals (UN-SDGs). While these sources have been traditionally used for various applications across different cultures and industries, it seems evident that their full potential has not yet been exploited, leaving these products more like an environmental burden rather than valuable resources. With innovation and well-targeted interdisciplinary collaborations, the potential of the fifth quarter can be fully realized. The present review intends to explore these low-value streams, their current utilization, and their potential to tackle the global challenges of increasing protein demands while preventing environmental degradation. Factors that limit widespread applications of the fifth quarter across industries and cultures will also be discussed.

Safety evaluation of the food enzyme catalase from porcine liver

The food enzyme catalase (EC 1.11.1.6) is obtained from porcine liver by Laboratorios Arroyo S.A. It is intended to be used in a broad range of food processes. The Panel noted that the manufacturing process involved the use of a solvent not permitted in the production of food ingredients which include food enzymes. In addition, the evidence provided showed that the manufacturing process could not be guaranteed to inactivate viruses originating from the starting material, including the human zoonotic pathogen Hepatitis E virus. Consequently, the Panel concluded that the use of catalase extracted from porcine liver may present a health risk.

Abda E. Recent advances and prospects for industrial waste management and product recovery for environmental appliances

Any material when utilized for a required period of time and segment, the leftover residues of those materials are known as waste. Enormous waste is generated during such wear and tear process of materials depending on the usage and functions in a routine lifestyle. Those generated waste when overloaded beyond the capacity of natural recycling processes, would influence the environment and human health. Hence, the waste generated from used materials should be managed according to the environmental impact. Even though wastes are also sometimes rich in organic compounds, nutrients, and energy resources, they are not experimented and managed appropriately. Recently, different feasible techniques are invented and followed to recover and reuse the efficient resources that can create and support sustainable livelihood by creating green economy effects by reducing waste. In this chapter, the emphasis has been given to providing an overview of recent advancements on bio-based waste management and product recoveries such as microbes mediated approaches, biorefineries for waste valorization, and bioenergy from industrial waste.

Dealing With Deadstock: A Case Study of Carnivore Conflict Mitigation From Southwestern Alberta

Livestock deaths are an unfortunate reality for livestock producers and dead livestock (i.e., deadstock) disposal options can have implications beyond the ranch itself. In Alberta, Canada, natural disposal (i.e., disposing of the carcass in a manner that allows for scavenging) has increased since the 2003 detection of bovine spongiform encephalopathy (BSE) in Canadian cattle. Prior to BSE, rendering companies removed deadstock for free. However, rendering companies started charging producers to remove deadstock to offset costs associated with new regulatory requirements enacted by the Canadian Food Inspection Agency, which has resulted in increased on-farm natural disposal of deadstock. This increase has ecological implications because deadstock are a major attractant for large carnivores. Carnivores feeding on deadstock are often near other agricultural attractants such as stored grain and feed, silage, and living livestock, which can exacerbate conflict potential and pose a risk to human safety. To help mitigate conflicts associated with deadstock, the Waterton Biosphere Reserve's (a local non-profit) Carnivores and Communities Program (CACP) supported expansion of community deadstock removal efforts beginning in 2009, including reimbursement of on-farm removal costs, bear-resistant deadstock bins, and a livestock compost facility (operational 2013–2014). Here, we present an evaluative case study describing the development, implementation, and results of the deadstock removal program, including the compost facility. We tracked the number of head of livestock removed each year, the number of participating landowners, the average cost per head, and total program costs. We also used an online survey to assess participants' perspectives of the deadstock removal program and future needs. To date, the CACP has removed &gt;5,400 livestock carcasses, representing between 15.1 and 22.6% of available carcasses in the program area, and 67.3% of livestock owners indicated they currently use the deadstock removal program to dispose of deadstock. Average cost to compost an animal was significantly less than other removal methods ($36.89 composting vs. $79.59 non-composting, one-tailed t-test, unequal sampling variances: t = 4.08, df = 5.87, p = 0.003). We conclude by discussing both ecological and social implications for deadstock removal as a conflict mitigation measure and make suggestions for future management considerations.

Valorization of municipal organic waste into purified lactic acid

Municipal organic waste (biowaste) consists of food derived starch, protein and sugars, and lignocellulose derived cellulose, hemicellulose, lignin and pectin. Proper management enables nutrient recycling and sustainable production of platform chemicals such as lactic acid (LA). This review gathers the most important information regarding use of biowaste for LA fermentation covering pre-treatment, enzymatic hydrolysis, fermentation and downstream processing to achieve high purity LA. The optimal approach was found to treat the two biowaste fractions separately due to different pre-treatment and enzyme needs for achieving enzymatic hydrolysis and to do continues fermentation to achieve high cell density and high LA productivity up to 12 g/L/h for production of both L and D isomers. The specific productivity was 0.4 to 0.5 h^-1 but with recalcitrant biomass, the enzymatic hydrolysis was rate limiting. Novel purification approaches included reactive distillation and emulsion liquid membrane separation yielding purities sufficient for polylactic acid production.

Compositional Features and Nutritional Value of Pig Brain: Potential and Challenges as a Sustainable Source of Nutrients

The goal of this study was to establish the nutritional value and compositional properties of the brains of crossbred pigs (Landrace-Large white-Duroc (LLD)), in order to realize the zero-waste concept and increase the use of by-products in the sustainable meat industry. Fat (9.25% fresh weight (fw)) and protein (7.25% fw) were the principal dry matters of pig brain, followed by carbohydrate and ash. Phospholipid and cholesterol had a 3:1 ratio. Pig brain had a red tone (L* = 63.88, a* = 5.60, and b* = 15.43) and a high iron content (66 mg/kg) due to a total heme protein concentration of 1.31 g/100 g fw. The most prevalent macro-element was phosphorus (14 g/kg), followed by potassium, sodium, calcium, and magnesium. Zinc, copper, and manganese were among the other trace elements discovered. The most prevalent nitrogenous constituents were alkali-soluble protein, followed by water-soluble protein, stromal protein, salt-soluble protein, and non-protein nitrogen. Essential amino acids were abundant in pig brain (44% of total amino acids), particularly leucine (28.57 mg/g protein), threonine, valine, and lysine. The total lipid, neutral, and polar lipid fractions of the pig brain had different fatty acid compositions. The largest amount was observed in saturated fatty acids (SFA), followed by monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Stearic acid and palmitic acid were the most common SFA. Oleic acid was the most prevalent MUFA, while docosahexaenoic acid was the most common PUFA. Thus, the pig brain can be used in food formulations as a source of nutrients.

Insight on Current Advances in Food Science and Technology for Feeding the World Population

While the world population is steadily increasing, the capacity of Earth to renew its resources is continuously declining. Consequently, the bioresources required for food production are diminishing and new approaches are needed to feed the current and future global population. In the last decades, scientists have developed novel strategies to reduce food loss and waste, improve food production, and find new ingredients, design and build new food structures, and introduce digitalization in the food system. In this work, we provide a general overview on circular economy, alternative technologies for food production such as cellular agriculture, and new sources of ingredients like microalgae, insects, and wood-derived fibers. We present a summary of the whole process of food design using creative problem-solving that fosters food innovation, and digitalization in the food sector such as artificial intelligence, augmented and virtual reality, and blockchain technology. Finally, we briefly discuss the effect of COVID-19 on the food system. This review has been written for a broad audience, covering a wide spectrum and giving insights on the most recent advances in the food science and technology area, presenting examples from both academic and industrial sides, in terms of concepts, technologies, and tools which will possibly help the world to achieve food security in the next 30 years.

Biotransformation of pork trimmings into protein hydrolysate using microbial proteases aided by response surface methodology

Meat processing generates significant amounts of by-products such as trimmings that require further valorization. In this study, pork trimmings were transformed with proteases to protein hydrolysates that may find applications as nutritional and/or flavouring ingredients. Four microbial proteases-Flavourzyme, Protamex, Alcalase, and Neutrase were explored to hydrolyze pork trimmings. Flavourzyme, which showed the highest degree of hydrolysis (DH), was selected to optimize the key hydrolytic parameters using response surface methodology (RSM) with Box-Behnken design. The optimal conditions were found to be 6: 100 (enzyme/substrate ratio), 50 °C, and pH 6 for a maximum DH at 48% after 6 h of hydrolysis. The protein hydrolysate was high in free amino acids (17 g/100 g dry weight), of which essential and taste-active amino acids accounted for 42% and 20%, respectively. The obtained hydrolysate may be considered suitable as a nutritional and/or flavouring ingredient.

Effect of processing on in vitro digestibility (IVPD) of food proteins

Proteins are important macronutrients for the human body to grow and function throughout life. Although proteins are found in most foods, their very dissimilar digestibility must be taking into consideration when addressing the nutritional composition of a diet. This review presents a comprehensive summary of the in vitro digestibility of proteins from plants, milk, muscle, and egg. It is evident from this work that protein digestibility greatly varies among foods, this variability being dependent not only upon the protein source, but also the food matrix and the molecular interactions between proteins and other food components (food formulation), as well as the conditions during food processing and storage. Different approaches have been applied to assess in vitro protein digestibility (IVPD), varying in both the enzyme assay and quantification method used. In general, animal proteins tend to show higher IVPD. Harsh technological treatments tend to reduce IVPD, except for plant proteins, in which thermal degradation of anti-nutritional compounds results in improved IVPD. However, in order to improve the current knowledge about protein digestibility there is a vital need for understanding dependency on a protein source, molecular interaction, processing and formulation and relationships between. Such knowledge can be used to develop new food products with enhanced protein bioaccessibility.

Bioactive Compounds of Porcine Hearts and Aortas May Improve Cardiovascular Disorders in Humans

Functional foods promote health benefits in human metabolism, with bioactive compounds acting as therapeutic agents. The aim was to investigate the biological effects of a pâté made of pork hearts and aortas, minced, sterilised and packed in tins. Adults (61–66 years old) with a body mass index of 26.4–60.7 kg/m² (n = 36) were randomly divided into two groups: one group consumed a low-calorie diet (LCD), while the other consumed an LCD with the developed meat product (MP) for 28–30 days. Serum biochemical parameters, anthropometry and blood pressure were measured. Consumption of an LCD + MP by experimental group participants helped to maintain reduced cholesterol levels. The difference in total cholesterol was significantly different (p = 0.018) from that of the control group, mainly due to the difference in low-density lipoprotein cholesterol (p = 0.005). Six peptides with potential cholesterol-binding properties and four peptides with potential antioxidant activity were identified in the MP, while elevation of the content of two peptides with potential angiotensin-converting enzyme-inhibitory activity was detected in patients’ plasma. Intervention with the MP can be considered as a supportive therapy to the main treatment for medical cardiovascular diseases due to a positive effect on serum cholesterol.