Influence of culinary practices on protein and lipid oxidation of chicken meat burgers during cooking and in vitro gastrointestinal digestion

Natural antioxidants (rosemary and parsley) in microwaved ground meat patties: effects of in vitro digestion

BACKGROUND

Minimizing food oxidation remains a challenge in several environments. The addition of rosemary extract (150 mg kg-1) and lyophilized parsley (7.1 g kg-1) at equivalent antioxidant activity (5550 μg Trolox equivalents kg-1) to meat patties was assessed in terms of their effect during microwave cooking and after being subjected to an in vitro digestion process.

RESULTS

Regardless of the use of antioxidants, cooking caused a decrease of the fat content as compared to raw samples, without noticing statistical differences in the fatty acid distribution between raw and cooked samples [44%, 47% and 6.8%, of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively]. However, the bioaccessible lipid fraction obtained after digestion was less saturated (around 34% SFA) and more unsaturated (35% MUFA +30% PUFA). Cooking caused, in all types of samples, an increased lipid [thiobarbituric acid reactive substances (TBARS)] and protein (carbonyls) oxidation values. The increase of TBARS during in vitro digestion was around 7 mg malondialdehyde (MDA) kg-1 for control and samples with parsley and 4.8 mg MDA kg-1 with rosemary. The addition of parsley, and particularly of rosemary, significantly increased the antioxidant activity (DPPH) of cooked and digested microwaved meat patties.

CONCLUSION

Whereas rosemary was effective in minimizing protein oxidation during cooking and digestion as compared to control samples, parsley could only limit it during digestion. Lipid oxidation was only limited by rosemary during in vitro digestion. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Meat crust as a novel food ingredient to regulate lipid peroxidation and oxidative stress

Pan Fry (PF) is a common heating treatment however, there is limited data on meat oxidation after PF using direct contact with an uncoated iron pan. After PF, a crust is formed, and in this study, we aim to evaluate the potential anti-oxidation and anti-lipid peroxidation capacity of such crust. Ground beef and turkey meat were heat treated using PF or microwave. Lipid peroxidation was evaluated using malondialdehyde accumulation. PF meat generated lower lipid peroxidation levels versus microwave-heated meat. Iron PF has decreased lipid peroxidation versus Teflon pan heating. The crust significantly lowered lipid peroxidation and possessed millard reaction products (MRPs), strong reducing abilities, iodine removal capacity, and some iron chelation capacity. We demonstrated that the crust substantially decreases lipid peroxidation levels in various systems and can be used as a novel seminatural antioxidant ingredient, which may lead to extended shelf life and protects various food products.

Cooking-Induced Oxidation and Structural Changes in Chicken Protein: Their Impact on In Vitro Gastrointestinal Digestion and Intestinal Flora Fermentation Characteristics

Meat digestion and intestinal flora fermentation characteristics are closely related to human dietary health. The present study investigated the effect of different cooking treatments, including boiling, roasting, microwaving, stir-frying, and deep-frying, on the oxidation of chicken protein as well as its structural and digestion characteristics. The results revealed that deep-fried and roasted chicken exhibited a relatively higher degree of protein oxidation, while that of boiled chicken was the lowest (p < 0.05). Both stir-frying and deep-frying led to a greater conversion of the α-helix structure of chicken protein into a β-sheet structure and resulted in lower protein gastrointestinal digestibility (p < 0.05), whereas roasted chicken exhibited moderate digestibility. Further, the impact of residual undigested chicken protein on the intestinal flora fermentation was assessed. During the fermentation process, roasted chicken generated the highest number of new intestinal flora species (49 species), exhibiting the highest Chao 1 index (356.20) and a relatively low Simpson index (0.88). Its relative abundance of Fusobacterium was the highest (33.33%), while the total production of six short-chain fatty acids was the lowest (50.76 mM). Although stir-fried and deep-fried chicken exhibited lower digestibility, their adverse impact on intestinal flora was not greater than that of roasted chicken. Therefore, roasting is the least recommended method for the daily cooking of chicken. The present work provides practical advice for choosing cooking methods for chicken in daily life, which is useful for human dietary health.

Changes in bioactive compounds present in beef burgers formulated with walnut oil gelled emulsion as a fat substitute during in vitro gastrointestinal digestion

BACKGROUND

The partial or total substitution of animal fat by a gelled emulsion elaborated with cocoa bean shell and walnut oil in beef burgers was assessed in terms of the stability of the bioactive compounds (polyphenolic and methylxanthines compounds, and fatty acid profile), bioaccessibility, colon-available indices (CAIs), and lipid oxidation after in vitro gastrointestinal digestion (GID).

RESULTS

No free polyphenolic compounds were detected in the soluble fraction after the GID of reformulated beef burgers. Reductions were obtained in the bound fraction with respect to the undigested sample from 47.57 to 53.12% for protocatechuic acid, from 60.26 to 78.01% for catechin, and from 38.37 to 60.95% for epicatechin. The methylxanthine content decreased significantly after GID. The theobromine content fell by between 48.41 and 68.61% and the caffeine content was reduced by between 96.47 and 97.95%. The fatty acid profile of undigested samples was very similar to that of digested samples. In the control burger the predominant fatty acids were oleic acid (453.27 mg g-1 ) and palmitic acid (242.20 mg g-1 ), whereas in reformulated burgers a high content of linoleic acid (304.58 and 413.35 mg g-1 ) and α-linolenic acid (52.44 and 82.35 mg g-1 ) was found. As expected, both undigested and digested reformulated samples presented a higher degree of oxidation than the control sample.

CONCLUSIONS

The reformulated beef burgers with cocoa bean shells flour and walnut oil were a good source of bioactive compounds, which were stable after in vitro gastrointestinal digestion. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Assessment of Chemical, Physico-Chemical and Sensory Properties of Low-Sodium Beef Burgers Formulated with Flours from Different Mushroom Types

It is now widely demonstrated that excessive salt consumption can cause various health problems, and meat products are among the foods most consumed with a high salt content. For that, the aim of this work was to assess the effects of the utilization of flours obtained from oyster mushrooms (Pleurotus ostreatus), button mushrooms (Agaricus bisporus), and portobello mushrooms (Agaricus brunnescen) as salt replacers on chemical, physicochemical, and sensory properties of beef burgers. The fat and protein content was not affected by the inclusion of mushroom flour, while the sodium content was reduced by 55-61% compared to the control sample. The control sample had the lowest values for cooking loss and shrinkage (12.29 and 18.69%, respectively) whilst the reformulated samples had higher values ranging between 16.08 and 18.88% for cooking loss, respectively, and between 19.55 and 28.25% for shrinkage, respectively. The reformulated samples showed higher lipid oxidation values (ranging from 0.18 and 0.20 mg malondialdehyde/kg sample) than the control sample. Sensorially, all parameters analyzed were not affected by the replacement of sodium chloride by the different mushroom flours. The use of flours obtained from different mushroom flours is a viable alternative to be used as sodium chloride replacers in the preparation of beef burgers.

Use of Pleurotus ostreatus to Enhance the Oxidative Stability of Pork Patties during Storage and In Vitro Gastrointestinal Digestion

Lipid and protein oxidation are the major causes of meat quality deterioration. Edible mushrooms have been proposed as a strategy to prevent quality deterioration during cold storage. This study aimed to assess the effects of Pleurotus ostreatus powder (POP) on the oxidative stability of pork patties during cold storage and after in vitro gastrointestinal digestion (ivGD). Pork patties were subjected to four treatments: control (without antioxidant), T1 (2% POP, w/w) and T2 (5% POP, w/w), and T3 as positive control (0.02% BHT, fat basis). POP aqueous, ethanolic, and aqueous ethanol extract were subjected to phytochemical and antioxidant assays. Raw pork patties were subjected to a chemical proximate composition evaluation. At the same time, raw and cooked pork patties were stored at 2 °C for 9 days and subjected to meat quality measurements. Furthermore, the total antioxidant activity of cooked pork patties was determined after ivGD. Results showed that POP ethanol extract showed the highest polysaccharide, phenol, and flavonoid content, as well as antiradical and reducing power properties. POP incorporation into raw and cooked pork patties enhances meat quality traits, including pH, water-holding capacity, cooking-loss weight, texture, color, lipid, and protein oxidation (p < 0.05). Furthermore, incorporating POP into cooked samples increases the phytochemical content and antioxidant activity during ivGD. In conclusion, POP has great potential as a natural antioxidant for meat products.

Free iron rather than heme iron mainly induces oxidation of lipids and proteins in meat cooking

In this study, the relationship between different forms of iron (free or binding) and oxidation of lipids, proteins in meat system were investigated. Pork tenderloin was heated in 80 °C water bath for 0, 30, 60, 120, 180, 240, 300 min. Compared with control group, Equal and Treble deferiprone group confirmed that free iron was the main oxidizing substance. Moreover, adding exogenous heme caused slight increase of meat oxidation (p < 0.05). At the same time, the antioxidant properties of deferiprone were also evaluated and it shows few antioxidant properties. This study also found that the oxidation of lipid by free iron was more serious than protein. These results suggested that controlling free iron and production of free iron from heme is a potential approach for reducing the oxidative damage of lipid and protein in meat cooking.

Fat Oxidation of Fatty Fish vs. Meat Meal Diets Under in vitro Standardized Semi-Dynamic Gastric Digestion

Meat and fish are introduced into the diet as a source of protein, but these muscle foods present different fatty acid (FA) compositions and different lipid stabilities. Fatty fish is expected to oxidize due to its higher content of polyunsaturated FA (PUFA), whereas the higher heme-Fe content of red meat will also affect lipid stability. Combining other food ingredients within a meal also influences lipid oxidation, which will not stop after meals intake. This is due to the acidic environment of the stomach together with the presence of metallic ions, a process that is scarcely understood. The goal of this study was to evaluate the oxidation of fatty fish vs. meat meal diets under in vitro standardized semi-dynamic gastric conditions and FA release from the stomach to the duodenum. Meal diets composed by 25% beef meal (BM) or fatty fish meal (FM), 25% fried potatoes, and 50% sugar soft drink were prepared. Proximate composition, FA and amino acid profiles, and meals quality indices were evaluated. Their differences in composition led to different total gastric digestion time of 242.74 (BM) and 175.20 (FM) minutes. Using the INFOGEST semi-dynamic gastric model, 4 gastric emptying (GE) were simulated in both meals. In each GE, FA profile and lipid oxidation products (LOPs) formation were assessed. As a result, more than 50% FA release to the duodenum occurred in GE1, whose percentage decreased with the time of digestion. FM exhibited the highest LOPs formation, which corroborates the high peroxidizability index measured for this meal diet. Higher LOPs formation occurred in the later GEs, which released less FA. This suggests that higher times of residence in the stomach increase FA oxidation. This study shows a higher formation of LOPs during digestion of FM using a whole meal approach. These results relate to its richness in PUFAs compared to BM. Despite higher LOPs formation, FM digests that reached duodenum still contain higher content of unoxidized PUFAs compared with BM and a desirable ω3/ω6 PUFAs ratio of ~0.43. LOPs formation in PUFA-rich meals could be reduced if those meals have a low caloric value, avoiding large times of residence in the stomach and consequently high levels of oxidation.

Nutritional, Physicochemical, and Endogenous Enzyme Assessment of Raw Milk Preserved under Hyperbaric Storage at Variable Room Temperature

Raw milk (a highly perishable food) was preserved at variable room temperature (RT) under hyperbaric storage (HS) (50-100 MPa) for 60 days and compared with refrigeration (RF) under atmospheric pressure (AP) on quality, nutritional, and endogenous enzyme activity parameters. Overall, a comparable raw milk preservation outcome was observed between storage under AP/RF and 50/RT after 14 days, with similar variations in the parameters studied indicating milk degradation. Differently, even after 60 days (the maximum period studied) under 75-100/RT, a slower milk degradation was achieved, keeping most of the parameters similar to those of milk prior to storage, including pH, titratable acidity, total solid content, density, color, viscosity, and volatile organic and fatty acid profiles, but with higher free amino acid content, signs of an overall better preservation. These results indicate an improved preservation and enhanced shelf life of raw milk by HS/RT versus RF, showing HS potential for milk and highly perishable food preservation in general.

Effect of Static Magnetic Field Assisted Thawing on Physicochemical Quality and Microstructure of Frozen Beef Tenderloin

Although freezing is the most common and widespread way to preserve food for a long time, the accumulation of microstructural damage caused by ice crystal formation during freezing and recrystallization phenomena during thawing tends to degrade the quality of the product. Thus, the side effects of the above processes should be avoided as much as possible. To evaluate the effect of different magnetic field strength assisted thawing (MAT) on beef quality, the indicators associated with quality of MAT-treated (10-50 Gs) samples and samples thawed without an external magnetic field were compared. Results indicated that the thawing time was reduced by 21.5-40% after applying MAT. Meat quality results demonstrated that at appropriate magnetic field strengths thawing loss, TBARS values, cooking loss, and shear force were significantly decreased. Moreover, by protecting the microstructure of the muscle, MAT significantly increased the a∗ value and protein content. MAT treatment significantly improved the thawing efficiency and quality of frozen beef, indicating its promising application in frozen meat thawing.

Microencapsulated procyanidins by extruding starch improved physicochemical properties, inhibited the protein and lipid oxidant of chicken sausages

Microencapsulated procyanidins by extruding starch (MPS) were used in meat and meat products as an antioxidant for their simple production process and high stability. This study investigated the controlled released properties of MPS and their effect on antioxidant capacity, physicochemical properties, and sensory qualities of chicken sausages during 4°C storage within 28 days. Antioxidant capacity, particle size analysis, and simulated digestion in vitro demonstrated that microencapsulation by extruding starch delayed the procyanidins release. The reduced crystal structure of MPS was determined by the morphology observation (SEM) and the decrease of the typical diffraction peak at 2θ of 20.9° (XRD). The MPS-added sausage had a higher (p < 0.05) ABTS and DPPH radical scavenging ratio (97.6% and 67.3%) and sulfhydryl contents (114.69 nmol/g protein) than other groups. Moreover, lower (p < 0.05) thiobarbituric acid reactive substances (TBARS) (0.67 mg MDA/kg sausage) and carbonyl values (3.24 nmol/mg protein) were detected in MPS-added sausages than others at the end of storage. The MPS addition increased redness (a* value) and decreased the lightness (L* value). The sensory analysis suggested that the sausage with the increased redness was favorable. These results denominated that MPS was an alternative antioxidant in chicken sausages. Practical Application: In this study, microencapsulated procyanidins were prepared by extrusion technology, and the effect on the quality of chicken sausages was investigated, which provides an alternative natural antioxidant for meat and meat products.

Improvement strategies for quality defects and oxidation of pale, soft and exudative (PSE)-like chicken meat: effects of domestic cooking and core temperature

In practice, this study will help to better elucidate the relationship between oxidation profile and meat quality, and provide consumers with recommendations for consuming PSE-like meat.

An evaluation of biochemical, structural and volatile changes of dry-cured pork using a combined ion mobility spectrometry, hyperspectral and confocal imaging approach

BACKGROUND

Food processing induces various modifications that affect the structure, physical and chemical properties of food products and hence the acceptance of the product by the consumer. In this work, the evolution of volatile components, 2-thiobarbituric acid reactive substances (TBARS), moisture content (MC) and microstructural changes of pork was investigated by hyperspectral (HSI) and confocal imaging (CLSM) techniques in synergy with gas chromatography-ion mobility spectrometry (GC-IMS). Models based on partial least squares regression (PLSR) were developed using the full HSI spectrum variables as well as optimum variables selected through a competitive adaptive reweighted sampling algorithm.

RESULTS

Prediction results for MC and TBARS using multiplicative scatter correction pre-processed spectra models demonstrated greater efficiency and predictability with determination coefficient of prediction of 0.928, 0.930 and root mean square error of prediction of 0.114, 1.002, respectively. Major structural changes were also observed during CLSM imaging, which were greatly pronounced in pork samples oven cooked for 15 and 20 h. These structural changes could be related to the denaturation of the major meat components, which could explain the loss of moisture and the formation of TBARS visualized from the HSI chemical distribution maps. GC-IMS identified 35 volatile components, including hexanal and pentanal, which are also known to have a higher lipid oxidation specificity.

CONCLUSION

The synergistic application of HSI, CLSM and GC-IMS enhanced data mining and interpretation and provided a convenient way for analyzing the chemical, structural and volatile changes occurring in meat during processing. © 2021 Society of Chemical Industry.

Lipid oxidation and aldehyde formation during in vitro gastrointestinal digestion of roasted scallop (Patinopecten yessoensis) - the role of added antioxidant of bamboo leaves

This study investigated lipid oxidation and aldehyde formation in roasted scallop during in vitro gastrointestinal digestion, and the effects of co-digestion of antioxidant of bamboo leaves (AOB) on this process. The results showed that the contents of lipid hydroperoxides (LOOH), conjugated dienes (CD), and Schiff bases (SB) were increased during gastrointestinal digestion. Besides, malondialdehyde (MDA) levels and total aldehyde formation decreased initially at the gastric stage but increased at the intestinal stage. The results of HPLC-ESI-MS/MS analysis showed that the contents of hexanal (HEX), trans, trans-2,4-octadienal (ODE), trans, trans-2,4-decadienal (DDE), 4-hydroxyhexenal (HHE) and 4-hydroxynonenal (HNE) in the digestive juices were all initially decreased and then increased during gastrointestinal digestion. Meanwhile, the content of acrolein, propanal, and trans-2-pentenal at the end of intestinal digestion was lower than that in the initial stage of gastric digestion. Additionally, the digestion of roasted scallop caused significant oxidation of polyunsaturated fatty acids (PUFAs) and release of free fatty acids (FFA) in the intestinal phase, which were positively related to aldehyde production. However, co-digestion of AOB significantly reduced lipid oxidation and formation of lipid oxidation products (LOOH, CD, SB, and aldehyde) during gastrointestinal digestion, indicating that the addition of AOB was effective in reducing gastrointestinal lipid oxidation.

In vitro gastric bioaccessibility of avocado peel extract in beef and soy-based burgers and its impact on Helicobacter pylori risk factors

The objective of the present study was to investigate the impact of phenolic-rich avocado peel extract (APE) as an ingredient in beef and soy-based burgers to increase their antioxidant activity, reduce lipid and protein oxidation during gastric digestion, and inhibit urease and anhydrase carbonic activity, which are considered as key factors in the main steps of Helicobacter pylori adhesion in the stomach. The gastric bioaccessible fraction of soy and beef burgers with added 0.5% APE obtained by in vitro digestion exhibited a higher content of phenolic compounds, including monomeric and oligomeric (epi)catechin forms and quercetin, and reduced levels of thiobarbituric acid-reactive substances (TBARS) and carbonyls (49% to 73% and 57% to 60%, respectively) when compared with control burgers. Moreover, the burgers with APE inhibited urease and carbonic anhydrase activity. Results generally showed that including APE reduces the primary risk factors associated with H. pylori infection.

Protein carbonylation in food and nutrition: a concise update

Protein oxidation is a topic of indisputable scientific interest given the impact of oxidized proteins on food quality and safety. Carbonylation is regarded as one of the most notable post-translational modifications in proteins and yet, this reaction and its consequences are poorly understood. From a mechanistic perspective, primary protein carbonyls (i.e. α-aminoadipic and γ-glutamic semialdehydes) have been linked to radical-mediated oxidative stress, but recent studies emphasize the role alternative carbonylation pathways linked to the Maillard reaction. Secondary protein carbonyls are introduced in proteins via covalent linkage of lipid carbonyls (i.e. protein-bound malondialdehyde). The high reactivity of protein carbonyls in foods and other biological systems indicates the intricate chemistry of these species and urges further research to provide insight into these molecular mechanisms and pathways. In particular, protein carbonyls are involved in the formation of aberrant and dysfunctional protein aggregates, undergo further oxidation to yield carboxylic acids of biological relevance and establish interactions with other biomolecules such as oxidizing lipids and phytochemicals. From a methodological perspective, the routine dinitrophenylhydrazine (DNPH) method is criticized not only for the lack of accuracy and consistency but also authors typically perform a poor interpretation of DNPH results, which leads to misleading conclusions. From a practical perspective, the biological relevance of protein carbonyls in the field of food science and nutrition is still a topic of debate. Though the implication of carbonylation on impaired protein functionality and poor protein digestibility is generally recognized, the underlying mechanism of such connections requires further clarification. From a medical perspective, protein carbonyls are highlighted as markers of protein oxidation, oxidative stress and disease. Yet, the specific role of specific protein carbonyls in the onset of particular biological impairments needs further investigations. Recent studies indicates that regardless of the origin (in vivo or dietary) protein carbonyls may act as signalling molecules which activate not only the endogenous antioxidant defences but also implicate the immune system. The present paper concisely reviews the most recent advances in this topic to identify, when applicable, potential fields of interest for future studies.

Effect of vacuum frying and atmospheric frying on the quality and protein oxidation of squid (Loligo chinensis)

Squid are commercial marine species that have high nutritional value. This study aimed to compare the influences of vacuum frying and atmospheric frying on the physicochemical properties and protein oxidation of three main parts (ring, tentacle, and fin) of the squid Loligo chinensis. The results showed that the vacuum-fried (VF) group had lower moisture and total fat contents and looser microstructures than the atmospheric-fried (AF) group. The amino acid contents and molecular weight revealed that the proteins were well preserved during vacuum frying. Carbonyl content in the VF ring, tentacle, and fin samples increased nearly 2.53-, 1.54-, and 2.56-fold, respectively, compared to that in the corresponding fresh group, but these increases were lower than those of the corresponding AF group. In addition, the secondary structures of proteins revealed a slight decrease in the α-helix and β-turn contents and a significant increase in the β-sheet content during vacuum frying. Therefore, vacuum frying can be used as an efficient processing method to conserve the high nutritive quality of the product. PRACTICAL APPLICATION: As a developing alternative technology to prepare healthier fried products, vacuum frying has been the focus of recent researches. Vacuum frying produced squid products that had lower TBARS values, carbonyl contents, and Schiff base substances compared to atmospheric frying. And the protein secondary structures of the vacuum-fried group retained better. The study proved that vacuum frying could be an effective method with the advantages of high protein stability and product quality.

Thermal processing implications on the digestibility of meat, fish and seafood proteins

Thermal processing is an inevitable part of the processing and preparation of meat and meat products for human consumption. However, thermal processing techniques, both commercial and domestic, induce modifications in muscle proteins which can have implications for their digestibility. The nutritive value of muscle proteins is closely related to their digestibility in the gastrointestinal tract and is determined by the end products that it presents in the assimilable form (amino acids and small peptides) for the absorption. The present review examines how different thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect the digestibility of muscle proteins in the gastrointestinal tract. By altering the functional and structural properties of muscle proteins, thermal processing has the potential to influence the digestibility negatively or positively, depending on the processing conditions. Thermal processes such as sous-vide can induce favourable changes, such as partial unfolding or exposure of cleavage sites, in muscle proteins and improve their digestibility whereas processes such as stewing and roasting can induce unfavourable changes, such as protein aggregation, severe oxidation, cross linking or increased disulfide (S-S) content and decrease the susceptibility of proteins during gastrointestinal digestion. The review examines how the underlying mechanisms of different processing conditions can be translated into higher or lower protein digestibility in detail. This review expands the current understanding of muscle protein digestion and generates knowledge that will be indispensable for optimizing the digestibility of thermally processed muscle foods for maximum nutritional benefits and optimal meal planning.

1H NMR Study of the In Vitro Digestion of Highly Oxidized Soybean Oil and the Effect of the Presence of Ovalbumin

Oxidized lipids containing a wide variety of potentially toxic compounds can be ingested through diet. However, their transformations during digestion are little known, despite this knowledge being essential in understanding their impact on human health. Considering this, the in vitro digestion process of highly oxidized soybean oil, containing compounds bearing hydroperoxy, aldehyde, epoxy, keto and hydroxy groups, among others, is studied by ¹H nuclear magnetic resonance. Lipolysis extent, oxidation occurrence and the fate of oxidation products both present in the undigested oil and formed during digestion are analyzed. Furthermore, the effect during digestion of two different ovalbumin proportions on all the aforementioned issues is also addressed. It is proved that polyunsaturated group bioaccessibility is affected by both a decrease in lipolysis and oxidation occurrence during digestion. While hydroperoxide level declines throughout this process, epoxy-compounds, keto-dienes, hydroxy-compounds, furan-derivatives and n-alkanals persist to a great extent or even increase. Conversely, α,β-unsaturated aldehydes, especially the very reactive and toxic oxygenated ones, diminish, although part of them remains in the digestates. While a low ovalbumin proportion hardly affects oil evolution during digestion, at a high level it diminishes oxidation and reduces the concentration of potentially bioaccessible toxic oxidation compounds.

Prediction of Thiol Group Changes in Minced Raw and Cooked Chicken Meat with Plant Extracts-Kinetic and Neural Network Approaches

Simple Summary

Demand for poultry meat (chickens and turkeys) is constantly increasing. The upward trend in the production and consumption of poultry meat has two reasons. The first is the financial aspect because chicken meat is relatively cheap. The second reason is the nutritional and health aspect. Although the meat has high nutritional, dietary, culinary, technological, and sensory values, it is very susceptible to undesirable changes during storage, mainly due to the growth of microflora but also due to lipid and protein oxidation. The use of plant extracts in food technology is multifunctional, as they exhibit antioxidant and antibacterial effects and have a beneficial effect on the texture of meat and meat products. Moreover, the antioxidant effect of compounds isolated from plants may influence consumer health. Antioxidants of plant origin can be used as an additive to animal feed, as well as a component of stuffing or marinating mixes for meat. In addition, they are used in the coating of raw materials or in active packaging for food products. So far, many studies have shown the positive effect of plant and plant extract addition to meat on the oxidative status of its protein. However, the predictive approach to protein oxidation in raw meat is still little described. This study has demonstrated the potential usefulness of the kinetic model as well as models based on artificial neural networks (ANNs) to the realistic prediction of protein oxidation expressed as thiol group (SH) changes in raw and cooked chicken meat during storage. Such predictive models allow us to predict oxidative changes in minced meat under different time and temperature conditions as minced meat is particularly susceptible to oxidation through exposure to oxygen during the mincing process itself and through the increased contact surface with oxygen. This knowledge is very useful in designing food products and predicting their shelf-life. Additionally, the effectiveness of various spices in the raw and cooked meat system were compared. Meat is a very complex system and, according to the research, there is no direct correlation between the anti-oxidant activity of the spice itself and its antioxidant effectiveness in the product.

Abstract

The aim of the study was to develop predictive models of thiol group (SH) level changes in minced raw and heat-treated chicken meat enriched with selected plant extracts (allspice, basil, bay leaf, black seed, cardamom, caraway, cloves, garlic, nutmeg, onion, oregano, rosemary, and thyme) during storage at different temperatures. Meat samples with extract addition were stored under various temperatures (4, 8, 12, 16, and 20 °C). SH changes were measured spectrophotometrically using Ellman’s reagent. Samples stored at 12 °C were used as the external validation dataset. SH content decreased with storage time and temperature. The dependence of SH changes on temperature was adequately modeled by the Arrhenius equation with average high R² coefficients for raw meat (R² = 0.951) and heat-treated meat (R² = 0.968). Kinetic models and artificial neural networks (ANNs) were used to build the predictive models of thiol group decay during meat storage. The obtained results demonstrate that both kinetic Arrhenius (R² = 0.853 and 0.872 for raw and cooked meat, respectively) and ANN (R² = 0.803) models can predict thiol group changes in raw and cooked ground chicken meat during storage.

Pork Liver Pâté Enriched with Persimmon Coproducts: Effect of In Vitro Gastrointestinal Digestion on Its Fatty Acid and Polyphenol Profile Stability

Agrofood coproducts are used to enrich meat products to reduce harmful compounds and contribute to fiber and polyphenol enrichment. Pork liver pâtés with added persimmon coproducts (3 and 6%; PR-3 and PR-6, respectively) were developed. Therefore, the aim was to study the effect of their in vitro gastrointestinal digestion on: the free and bound polyphenol profile (HPLC) and their colon-available index; the lipid oxidation (TBARs); and the stability of the fatty acid profile (GC). Furthermore, the effect of lipolysis was investigated using two pancreatins with different lipase activity. Forty-two polyphenols were detected in persimmon flour, which were revealed as a good source of bound polyphenols in pâtés, especially gallic acid (164.3 µg/g d.w. in PR-3 and 631.8 µg/g d.w. in PR-6). After gastrointestinal digestion, the colon-available index in enriched pâté ranged from 88.73 to 195.78%. The different lipase activity in the intestinal phase caused significant differences in bound polyphenols' stability, contributing to increased lipid oxidation. The fatty acids profile in pâté samples was stable, and surprisingly their PUFA content was raised. In conclusion, rich fatty foods, such as pâté, are excellent vehicles to preserve bound polyphenols, which can reach the colon intact and be metabolized by the intestinal microbiome.

Black, green, and pink pepper affect differently lipid oxidation during cooking and in vitro digestion of meat

Lipid oxidation products generated during meat digestion may contribute to the apparent epidemiological link between red meat intake and the risk of cardiovascular diseases and colorectal cancer. The aim of this work was to assess the lipid oxidation inhibitory activity of black, green, and pink pepper during cooking and in vitro digestion of meat. Peppers were characterized for their phenolic profiles by LC-ESI-MS and the antioxidant properties. Pink pepper showed the highest phenolic content and antioxidant activities. Then, the peppers were added to meat either before or after cooking, and the meat was subjected to in vitro digestion. Pink pepper added before cooking was the most effective, with an inhibition of 80% and 72% in lipid hydroperoxides and TBA-RS formation after digestion, respectively. These findings suggest that peppers, particularly pink pepper, can be used to minimize lipid oxidation in the gastro-intestinal tract and for the design of healthy dietary patterns.