Antioxidant peptides generated from chicken feet protein hydrolysates.

BACKGROUND: As major industrial poultry by-products, chicken feet are considered as notable sources of several bioactive molecules. The current work covers the processing of chicken feet proteins as substrates to be hydrolysed by combinations of three commercial enzymes (Alcalase®, Flavourzyme® and Protana® Prime) during different hydrolysis periods and the evaluation of the identified peptides having antioxidant activity after simulated gastrointestinal digestion. RESULTS: Enzymatic hydrolysis with Alcalase® and Protana® Prime combination for 4 h resulted in the highest activities. Reversed-phase high-performance liquid chromatographic separation of the purified hydrolysate yielded three active fractions that were further identified by nano-liquid chromatography-tandem mass spectrometry. The bioactivities of over 230 identified peptide sequences were estimated after simulated gastrointestinal digestion, and those peptides with the highest chance of exerting antioxidant activity were selected to be further synthesised and tested. In this sense, the synthesised dipeptides CF and GY showed the highest antioxidant capacity. CF presented IC50 values of 69.63 and 145.41 µmol L-1 in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) assays, respectively. In contrast, GY IC50 values were 15.27 and 10.06 µmol L-1 in ABTS and ORAC assays, respectively. Significant differences (P < 0.05) were registered between peptides in the same antioxidant assays. CONCLUSION: Overall, the findings emphasised the favourable impact of enzymatic hydrolysis with the obtaining of antioxidant peptides from poultry by-products that could be evaluated as a safe and economical source to retard oxidation in food systems. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Advanced Lipidomics in the Modern Meat Industry: Quality Traceability, Processing Requirement, and Health Concerns.

Over the latest decade, lipidomics has been extensively developed to give robust strength to the qualitative and quantitative information of lipid molecules derived from physiological animal tissues and edible muscle foods. The main lipidomics analytical platforms include mass spectrometry (MS) and nuclear magnetic resonance (NMR), where MS-based approaches [e.g., "shotgun lipidomics," ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS)] have been widely used due to their good sensitivity, high availability, and accuracy in identification/quantification of basal lipid profiles in complex biological point of view. However, each method has limitations for lipid-species [e.g., fatty acids, triglycerides (TGs), and phospholipids (PLs)] analysis, and necessitating the extension of effective chemometric-resolved modeling and novel bioinformatic strategies toward molecular insights into alterations in the metabolic pathway. This review summarized the latest research advances regarding the application of advanced lipidomics in muscle origin and meat processing. We concisely highlighted and presented how the biosynthesis and decomposition of muscle-derived lipid molecules can be tailored by intrinsic characteristics during meat production (i.e., muscle type, breed, feeding, and freshness). Meanwhile, the consequences of some crucial hurdle techniques from both thermal/non-thermal perspectives were also discussed, as well as the role of salting/fermentation behaviors in postmortem lipid biotransformation. Finally, we proposed the inter-relationship between potential/putative lipid biomarkers in representative physiological muscles and processed meats, their metabolism accessibility, general nutritional uptake, and potency on human health.

Chemical, technological, instrumental, microstructural, oxidative and sensory properties of emulsified sausages formulated with microparticulated whey protein to substitute animal fat.

The current study was conducted to investigate the utilization of microparticulated whey protein (MWP) in different levels (5% or 10%) as partial fat replacers in emulsified beef sausage formulations. Inclusion of MWP resulted in sausages having decreased amounts of fat and energy while increased amounts of protein. Both emulsion stability and processing yield were the highest in samples containing MWP. No differences were recorded in L* values of the sausages although both a* and b* values were higher in MWP sausages than in full-fat sausages regardless of MWP level. Increased amounts of MWP led to lower hardness, chewiness and adhesiveness. Micrographs brought out the organized and reticulated structure of the sausages containing 10% MWP. MWP did not cause unfavorable impacts in general sensory acceptance, besides, it was associated with increased oxidative stability. Overall, the findings highlighted the favorable effects of MWP in terms of nutritional, technological, sensory and oxidative quality indicating the possibility to design low-fat emulsified meat product formulations.

Cold-set or hot-set emulsion gels consisted of a healthy oil blend to replace beef fat in heat-treated fermented sausages.

The current work aimed to investigate the utilization of gelled emulsion (GE) systems stabilized either with cold or hot gelation consisted of peanut and linseed oils as fat replacers in fermented beef sausages. The reformulation provided a healthier lipid profile, that led to decreasing total lipid content, cholesterol, and SFAs (from 46.6% to 23.5%) meanwhile increasing both MUFAs (from 47.3% to 51.0%) and PUFAs (from 4.7% to 25.4%) as well as improving nutritional ratios (ω-6/ω-3, PUFA/SFA, IA, and IT). Cold-set GE caused less significant changes in instrumental color and protected PUFAs compared with hot-set GE, whereas hot-set GE provided advantages over cold-set GE in terms of microstructure, purge loss, and sensory scores. Replacement of beef fat fully by a hot-set GE system instead of using a fat-GE mixture was effective in reducing oxidation. The results demonstrated that utilization of different GE systems can be an effective strategy to contribute to the development of lipid-modified fermented meat products.

Peanut and linseed oil emulsion gels as potential fat replacer in emulsified sausages.

The study aimed to highlight the utilization of gelled emulsion (GE) systems containing peanut and linseed oils to replace beef fat partially or completely in emulsified sausages. Total fat content was reduced by up to 40% and energy content was lowered by up to 27% in reformulated products. Saturated fatty acids and cholesterol were successfully decreased while noticeable increments were provided in mono and poly-unsaturated fatty acids in sausages containing GE. Moreover, the reformulation procedure presented a good potential for increasing n-3 content, while lowering atherogenicity index, thrombogenicity index, and n-6/n-3 ratios. Although the incorporated GE resulted in color and texture alterations, it was effective to improve the technological attributes in terms of emulsion stability and cooking behaviors. In GE added samples, oxidative stability of final products decreased; however sensory features were acceptable. Overall results pointed out that GE systems could be successfully conveyed to emulsified sausage formulations to ensure a healthier lipid profile with good technological and sensory quality.

Formulating Reduced-fat Sausages with Quinoa or Teff Flours: Effects on Emulsion Characteristics and Product Quality.

This study dealt with the use of quinoa flour (QF) or teff flour (TF) as partial beef fat replacers in the formulation of emulsion-type sausages. A control (C) group was manufactured with 20% beef fat, while the other three groups were formulated with 10% beef fat plus 5% QF (Q), 5% TF (T), and 2.5% QF+2.5% TF (QT). Water-holding capacity of the emulsions was higher in Q (81.81%), T (82.20%), and QT (84.10%) samples than in C (64.83%) samples. Total expressible fluid and expressible fat were the lowest in Q and T samples, indicating the highest emulsion stability of those groups. Incorporation of QF and TF into formulations increased moisture and carbohydrate contents while decreased fat and energy values. Besides, the use of QF was effective to increase protein and dietary fiber contents. T sausages had lower luminosity (L*) and higher yellowness (b*) than C sausages, whilst Q sausages did not result in significant color changes. Higher cook yield values were recorded in Q (97.96%), T (98.21%), and QT (98.15%) samples compared with C (96.44%) samples. Inclusion of QF and TF to formulation led to lower hardness and gumminess, while utilization of TF was also effective to decrease chewiness. Consequently, healthier emulsified sausages were obtained by the inclusion of QF or TF that could decrease the fat content more than 50% without sacrificing overall quality, bringing advantages by quinoa over teff for increasing nutritional value and leading minimal modifications on color and texture.

Design of healthier beef sausage formulations by hazelnut-based pre-emulsion systems as fat substitutes.

In the present study, incorporation of pre-emulsified hazelnut oil (HO) plus hazelnut powder (HP) into sausage formulations as beef fat substitutes was investigated. Totally nine different treatments were formulated where beef fat (BF) was replaced with 0%, 50%, or 100% pre-emulsified HO with the addition of 0%, 3%, or 6% HP. Although pre-emulsion containing sausages had a higher lipid amount than BF containing sausages, SFAs went down from 47.2% to 13.6% while MUFAs increased from 41.8% to 71.3%, and PUFAs increased from 3.7% to 11.23% in sausages where BF was totally replaced. HO pre-emulsions were effective to improve nutritional ratios (P:S, IA, and IT) by means of lipid modification. Generally, no significant differences were recorded in textural and sensory parameters. Oxidative and technological quality could be maintained by HP addition to sausages with HO pre-emulsions. Consequently, the utilization of pre-emulsified HO and HP presented a good opportunity for introducing healthier oils and protecting the overall quality of emulsified meat products.

Protein oxidation and in vitro digestibility of heat-treated fermented sausages: How do they change with the effect of lipid formulation during processing?

In the present work, it was aimed to evaluate the oxidative stress indicators and in vitro digestibility during the processing of heat-treated Turkish sausages (sucuk) manufactured using different lipid formulations. The utilization of olive oil in sausage formulations had considerable impacts on proximate composition, pH, and water activity. The increased olive oil content increased primary lipid oxidation products, whereas it decreased the secondary ones. The use of olive oil increased the total carbonyl content, while it decreased the α-aminoadipic semialdehyde concentration. In general, pepsin, trypsin, and α-chymotrypsin activities of the treatments were similar to each other. The heat treatment during the processing significantly increased most of the oxidation markers. Though strong correlations were recorded between specific oxidation markers, no relationship was detected between oxidation parameters and in vitro digestibility. The results indicated that the lipid formulation and processing operations had significant impact on chemical and functional properties of heat-treated fermented sausages, within the complex interrelationships between oxidation mechanisms. PRACTICAL APPLICATIONS: The present work pointed out the changes and correlations between specific oxidation markers and in vitro digestibility of heat-treated fermented sausages during the production procedure. Oxidation reactions that occur in both proteins and lipids could have drastic impact on overall quality; for this reason, it is of great importance to provide the data for lightening these impacts regarding the product types and production applications. Since heat-treated muscle foods are widely manufactured to meet industrial needs, the data obtained from this research would contribute to understand the effects of formulation and processing operations in the formation of oxidation products and change in digestibility, thereby to pioneer further research on this topic.