Indicators Of Lipid Oxidation Research Articles

134 Does inclusion of high oleic soybeans in a swine finishing ration influence lipid oxidation and consumer taste panel preference?

Abstract The objective of this study was to determine if a swine finishing ration that included soybeans with greater concentration of oleic acid will have an impact on lipid oxidation and palatability of pork. Crossbred pigs [n = 72; initial body weight (BW) = 78 ± 9 kg] were blocked by BW, sex, and distributed within 18 pens. Each pen was randomly assigned to 1 of 3 experimental diets: a control soybean-meal (CTRL), extruded conventional soybean (CONV), and extruded high oleic acid soybean (TRU). Six different harvest groups (n = 12/group) were created across treatments to ensure uniformity of final BW. Therefore, experimental diets were offered to animals for 34, 37, 41, 42, 48, or 50 d, until all pigs reached 118 ± 5 kg. Carcasses were harvested, and chilled (2°C) for 24 h, before fabricating one 2.5 cm chop from the 11th rib of the right carcass side. The chops were vacuum packaged, aged for 7 d at 2 oC, and frozen (-18 oC) for later sensory analysis. Pork chops were thawed and cooked to 71 oC peak internal temperature (AMSA sensory guidelines) and fed to 115 consumers that rated overall liking, flavor, tenderness, juiciness, and presence of off flavors using hedonic scales. Also, a 50 g sample was obtained from each loin at the 12th rib, aged for 7 d and frozen at -80 oC for evaluation of malondialdehyde (MDA) as indicator of lipid oxidation. Subcutaneous fat samples were obtained from the first thoracic vertebra, frozen, and saved for fatty acid analysis. Data were analyzed using the MIXED procedure of SAS where diet was the main effect, while pen and breed were random effects. Repeated measures were used to analyze the consumer panel. Differences were considered significant at P ≤ 0.05 with pen as experimental unit. There were no significant differences (P > 0.05) for consumer perception of overall like, pork flavor, and presence of off flavors. Experimental diets impacted the perception of juiciness and tenderness (P < 0.05), where CONV was perceived as juicier and more tender than CTRL and TRU. As expected, diet affected the fatty acid profile of subcutaneous fat (P < 0.0001), with TRU having the greatest percentage for oleic (43.9 %), CONV the greatest percentage for linoleic and linolenic (17.8 and 1.3 % respectively), and CTRL for saturated fatty acids (34.5 %). Surprisingly, the lipid oxidation was not affected by the diet (P > 0.05). These results indicate that feeding extruded high oleic soybeans during the finishing period can modify the fatty acid profile in pork by improving the percentage of unsaturated fatty acids, so these soybeans can be considered as an alternative to improve nutritional value of pork without increasing the lipid oxidation or affecting the consumers acceptability.

Nutritional Value and Physicochemical Properties of Male and Female Broad-Breasted Bronze Turkey Muscle.

Colored varieties of turkeys, such as the broad-breasted Bronze, not currently subject to intensive breeding work, are kept only in amateur breeding and treated rather as ornamental poultry. They are raised in extensive systems, which undoubtedly affects the quality of the meat obtained. Consumers are looking for meat with specific and unique sensory qualities; hence, the interest in meat from turkeys with a slower-than-typical growth rate, such as the broad-breasted Bronze, is justified. The object of this research was to analyze the physicochemical properties and nutritional value (amino acid, fatty acid, and antioxidant profile) of the breast and thigh muscles of broad-breasted Bronze turkeys with regard to gender. It was shown that gender had little effect on muscle chemical composition, amino acid, and fatty acid content (p > 0.05), as well as most oxido-reduction indices. However, significant differences were noted in muscle quality traits such as color brightness (L*; turkeys > indors; p = 0.023), proportion of red (a*; turkeys < indors; p = 0.048) and yellow (b*; turkeys > indors; p = 0.039), and water absorption (turkeys < indors; p = 0.009). The type of muscle also had a significant effect on quality characteristics. Higher a*, b*, C*, pH, water absorption, and thermal leakage were shown in the femoral muscle (p < 0.001), while L* and h were higher in the pectoral muscle (p < 0.001). Turkey meat was characterized by a high proportion of unsaturated fatty acids (MUFA + PUFA ~68%), favorable FA index values, and low lipid oxidation indices. Thigh muscles (especially turkey) were more caloric, and contained significantly (p < 0.001) more fat and all major FA groups. Breast muscles (especially of turkeys) were characterized by a high protein content (about 25%) and a high proportion of essential amino acids. The data obtained indicate that broad-breasted Bronze turkeys can provide high-quality meat, and are an excellent option for meeting modern consumer needs.

Evaluating the Suitability of Orange Pulp Meal as a Partial Substitute of Corn on the Chemical and Sensorial Properties of Broiler Meat (Pectoralis major)

Background: The study aimed to assess the effect of a partial dietary substitution of corn with dried orange pulp (DOP) powder in broiler diets and their effect on Pectoralis major meat quality. Furthermore, the study investigated the relationship between physicochemical parameters and sensory characteristics of breast meat even of control and experimental broilers groups. Methods: Four dietary treatments namely basal diet (control), 5, 10 and 15% DOP were given to 200 broilers 16 days-old for 49 days. Throughout all breeding periods, the control group was fed a diet primarily composed of corn, soybean meal and wheat bran. The experimental groups were given the same initial diet as the control group, but their grower and finisher diets contained 5%, 10% and 15% of orange pulp powder respectively. Physicochemical parameters, proximate composition, lipid oxidation index and sensory characteristics of broiler breast muscle were determined. Result: Significant decreases in moisture and fats were observed in the experimental groups (P less than 0.0001). However, the experimental diets positively affected the lipid oxidation of breast meat samples, as indicated by the lower malondialdehyde content (P less than 0.05). The partial substitution with orange pulp powder did not show an effect (P greater than 0.05) on sensory attributes of breast meat except for overall acceptability by the degustation panel. According to the panel degustation results, the flavor in experimental diets breast meat had a significant correlation on some sensory characteristic like juiciness and color of experimental breast samples (P less than 0.001). Pearson’s correlation revealed that flavor of control breast meat was negatively correlated with 2 physicochemical parameters (pH and lipid peroxidation). Similarly, the flavor of experimental groups was negatively correlated with the sensory attributes (juiciness and color). Additionally, a significant positive correlation was found between juiciness and the parameters (color and pH) of experimental meat.

Effects of quercetin and l-ascorbic acid on heterocyclic amines and advanced glycation end products production in roasted eel and lipid-mediated inhibition mechanism analysis

Eel is a commercially important marine fish, frequently featured as sushi or roasted preparations. This study determined the formation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) in roasted eel and evaluated the inhibitory mechanism of quercetin and l-ascorbic acid on their formation. The results indicate a respective reduction of 75.07% and 84.72% in total HAs, alongside a decline of 23.03% and 39.14% in AGEs. Additionally, fundamental parameters of roasted eel, lipid oxidation indicators and precursors were measured to elucidate the mechanisms and impact of natural antioxidants on HAs and AGEs formation in roasted eel. Furthermore, endeavors were made to probe into the molecular mechanisms governing the influence of key differential lipids on the generation of HAs and AGEs through lipid-mics analysis. This research emphasizes the potential of natural antioxidants in preventing harmful substances formation during eel thermal processing, which is helpful to food manufacturers for healthier food production.

Nisina ou misturas de sais de ácidos orgânicos para produção de linguiça tipo Calabresa em escala industrial

Abstract This study aimed to produce Calabrese-type sausages on an industrial scale by incorporating nisin and mixtures of organic acids and their salts as preservatives. In addition, it was assessed the stability of the product during storage at 25 °C. Various formulations were investigated, each featuring distinct preservative combinations as follows: Treatment 1 (T1) included sodium lactate and sodium acetate; Treatment 2 (T2) contained sodium lactate, sodium acetate, citric acid, and nisin; Treatment 3 (T3) involved a combination of salt and nisin alongside sodium lactate; and a control group which utilized sodium lactate. The moisture values ranged from 55.84% to 57.45%, proteins from 18.53 to 19.07, and lipids from 17.04% to 19.15%, all following Brazilian legislation. The pH remained stable until 90 days of storage, with values of 6.30, 6.28, 6.05, and 6.23 for control, T1, T2, and T3, respectively. T2 presented higher acidity compared to the other formulations due to the presence of citric acid. The evaluated preservatives (T1, T2, and T3) showed lower lipid oxidation indices and inhibited microbial growth. Therefore, the evaluated preservatives have the potential to be used industrially because they maintain the characteristics of the product and ensure 120 days of storage at 25 °C.

Effects of different reducing carbohydrate types on the physicochemical characteristics of infant formula food stored for special medical purposes

The formula of food for special medical purpose has a direct impact on physicochemical stability, especially in hot climes and high temperature transport storage environments. An accelerated test (50 °C for 7 weeks) was used to analyze the mechanism of the physicochemical instability of formula A with lactose and maltodextrin, and formula B with maltodextrin. Deep dents and wrinkles were observed on the surface of the formula B, and more fat globules covered the surface of formula A particles after storage for a long time. Significantly higher amounts of furosine and Nε-carboxymethl-l-lysine (CML) were formed and the loss of available lysine was greater in formula A than in formula B. No significant difference was observed in lipid oxidation indicators between the two formulas. The results of this research demonstrated lactose was more active than maltodextrin and led to physicochemical instability.

The Potential of Lipid Oxidation on Non-Gluten Mocaf Cookies Incorporated with Chicken Meat-Carrot Puree

Cookies and crackers are the most popular snack in many countries. They are essentially made from wheat flour, which is also an issue as Indonesia is completely dependent on wheat imports. On the other hand, people with celiac disease could not consume wheat-derived products, including biscuits. Replacing the raw material of biscuits with local flour is one approach to reduce the use of wheat and help people with celiac disease. The aim of this study was to evaluate the quality of cookies made from modified cassava flour (mocaf), incorporated with chicken meat and carrot puree, from the point of view of lipid oxidation potential. The parameters observed were free fatty acids, peroxide value and thiobarbituric acid (TBA) number as indicators of lipid oxidation. The experimental design used was a completely randomised design with one factor, the ratio of chicken meat to carrot puree. The ratio was in 4 levels (F1 = 0:0 (control), F2 = 12.5%:37.5%, F3 = 25%:25%, F4 = 37.5%:12.5%). The results showed that the free fatty acid content had a range of 4.37-5.47 g/100 g, peroxide values 2.73-5.75 mq.eq/kg and TBA values 4.96-5.46 mg.mlonaldehyde/kg. Compared to the sample control (F1), the F4 formulation was considered to be the best biscuit in terms of low peroxide value and TBA values.

Early detection of acrolein precursors in vegetable oils by using proton transfer reaction – mass spectrometry

Acrolein is a toxic volatile compound derived from oxidative processes, that can be formed in foods during storage and cooking. This study employs proton transfer reaction mass spectrometry (PTR-MS) to detect acrolein precursors in vegetable oils by focusing on the m/z (mass-to-charge ratio) 57. To this purpose, hempseed, sesame, walnut, olive and linseed oils were stored for 168 h at 60 °C in presence of 2,2′-azobis(2-metilpropionitrile) (3 mM) radicals initiator. The evolution of m/z 57 by PTR-MS was also compared with traditional lipid oxidation indicators such as peroxide value, conjugated diene, oxygen consumption and, isothermal calorimetry. The obtained results were explained by the fatty acid composition and antioxidant capacity of the oils. Hempseed fresh oil presented a very low total volatile organic compounds (VOCs) intensity (5.6 kncps). Nonetheless, after storage the intensity increased ∼70 times. A principal component analysis (PCA) confirmed the potential of m/z 57 to differentiate fresh versus rancid hempseed oil sample. During an autoxidation experiment oils high in linolenic and linoleic acids showed higher m/z 57 emissions and shorter induction times: linseed oil (38 h) > walnut oil (47 h) > hempseed oil (80 h). The m/z 57 emission presented a high correlation coefficient with the total VOC signal (r > 0.95), conjugated dienes and headspace oxygen consumption. A PCA analysis showed a complete separation of the fresh oils on the first component (most significant) with the exception of olive oil. Walnut, hempseed and linseed oil were placed on the extreme right nearby total VOCs and m/z 57. The results obtained highlight the potential of PTR-MS for the early detection of oil autoxidation, serving as a quality control tool for potential acrolein precursor emissions, thereby enhancing food safety in the industry.

Stability and shelf life modeling of natural colorant from bee pollen

One of the main limitations for natural food colorants as potential replacements for synthetic alternatives is their stability and shelf life, which are determinant to their successful marketing. Bee pollen can be used as a source of natural pigments to substitute artificial colorants in the food, medicine, and cosmetics industries, showing advantages due to their bioactivity. This work studied the stability and shelf life of an oil-based carotenoid-rich extract (CRE) obtained from bee pollen via microwave-assisted extraction. Total carotenoid content (TCC), lipid oxidation indices, and color in the CIELAB space were evaluated during 90 days at three different temperatures: 30 °C, 45 °C, and 60 °C. The results showed that while the color remains stable, the TCC decreases and the peroxide index increases as a function of temperature. The overall CRE degradation kinetics was better modeled as a zero-order reaction and, with the Arrhenius equation, the shelf life of the colorant was determined as 37 months (at 20 °C) with a hue (hab) critical value of 70. These results demonstrate the high stability of a new type of natural colorant as well as the efficacy of bee pollen carotenoids in combination with oil lipids in color preservation.

Chemical Composition, Fatty Acid Profile, and Optimization of the Sacha Inchi (Plukenetia volubilis L.) Seed-Roasting Process Using Response Surface Methodology: Assessment of Oxidative Stability and Antioxidant Activity.

This study aimed to optimize the roasting conditions for sacha inchi (Plukenetia volubilis L.) seeds using the central composite design (CCD) of the response surface methodology (RSM). The antioxidant activity and oxidation indicators (peroxide and TBA values) were assessed, along with the impact of roasting on the fatty acid profile and chemical characterization of the seeds using gas chromatography. The results demonstrated that roasting partially increased the indicators of lipid oxidation in the oil extracted from roasted seeds, as well as the antioxidant activity of the seeds. The optimal roasting conditions were determined using CCD and RSM, resulting in an optimized temperature of 134.28 °C and 18.84 min. The fatty acid contents were not significantly affected by the roasting intensity, whereas a higher presence of amino acids was found in the seeds roasted at 140 °C for 15 min. In conclusion, it is suggested that the optimal roasting conditions for enhancing amino acid presence, improving antioxidant activity, and maintaining oxidative stability in sacha inchi seeds fall within the temperature range of 134-140 °C and a roasting duration of 15-20 min.

Insight into the effect of traditional frying techniques on glycosylated hazardous products, quality attributes and flavor characteristics of grass carp fillets.

This study aimed to evaluate the evolution of quality attributes, oxidation index, glycosylated hazardous products, aroma characteristics of grass carp fillets and their relationship under air-frying, roast-frying and pan-frying. With frying progressed, the level of carbonyl protein and lipid oxidation products increased significantly (following air-frying>pan-frying>roast-frying), and the latter decreased subsequently after 6min. Fillets possessed by frying increased significantly Nε-carboxymethyl-lysines (CML) and 5-hydroxymethylfurfural (5-HMF) levels, whose increment was pan-frying>air-frying>roast-frying. Compared to raw, eighty-seven volatiles were identified and the total concentrations of those increased gradually in air-frying, but then decreased up to 6min in roast-frying and pan-frying. Furthermore, significant correlations between CML, TBARS and 5-HMF, quality attributes, oxidation index; volatiles (VIP and/or OAV>1) and lipid oxidation index were obtained. Conclusively, fillets possessed by air-/roast-frying showed more lipid oxidation and alcohols/aldehydes, while pan-fried enriched CML and pyrazines.

Colour and pigment in raw ground meat incorporated crushed garlic during the refrigerated storage: Their relationship to lipolytic and volatilomic changes.

The effects of freshly crushed garlic incorporated in raw ground meat at different rates 0% to 2% on colour, pigment forms, TBARS, peroxide, free fatty acids and volatilomic were investigated during 96h storage at 4°C. With advancing storage time and increasing garlic rate from 0% to 2%, the redness (a*), colour stability, oxymyoglobin and deoxymyoglobin decreased, but metmyoglobin, TBARS, peroxide, free fatty acids (C6, C15-C17), and aldehydes and alcohols, especially hexanal, hexanol, benzaldehyde, increased. Principal component analysis based on pigment, colour, lipolytic and volatilomic changes classified successfully the meat samples. Metmyoglobin was positively correlated with lipid oxidation products (TBARS, hexanal), but the other pigment forms and colour parameters (a* and b* values) were negatively correlated. Increased metmyoglobin proportion and decreased redness and colour stability may be used as reliable indicators of lipid oxidation. Also, the incorporation of fresh garlic into ground meat was not promising to increase oxidative stability.

Lipid profile and oxidative stability of beef cuts from Urabá (Antioquia, Colombia): A step towards global commercialization

The commercialization of beef is an activity of great relevance for the department of Antioquia (Colombia), particularly in the Urabá region. The objective of this study was to evaluate the fat content, lipid composition, and some indicators of lipid oxidation and protein in beef from the Urabá region. 72 samples of beef cuts (loin and neck) of categories 3, 4 and 5 stars were analyzed. There were no statistical differences (p &gt; 0.05) between the fat content of cuts from the neck (11.64 ± 7.25 %) and loin (10.49 ± 5.60 %), or in the amount of saturated, monounsaturated, and polyunsaturated fat. There was no difference between the samples evaluated for lipid oxidation (TBARS). The lowest protein oxidation (4.48 ± 0.21 nmol carbonyl compounds/mg protein) and peroxide values (2.71 ± 0.12 mEq oxygen/kg sample) coincided with the samples with the lowest total fat content. The results provide tools for establishing quality standards for meat from this region that will allow it to enter new markets in the future.  

The correlation among residual nitrites, biogenic amines, N-nitrosamine formation, and degradation occurrence of punicalagin α/β, rosmarinic acid, carnosol, and carnosic acid in extract-treated sausage during storage.

The aim of this study was to investigate the relation between residual α- and β-punicalagin in Punica granatum L.; PPE and rosmarinic acid, carnosol, and carnosic acid in Salvia eremophila (SE) with residual nitrites, biogenic amines (cadaverine, putrescine, and histamine), N-nitrosodimethylamine (NDMA), microbial counts, lipid oxidation indices, and color values in extract-treated sausage over 14 days of storage. Sausage containing SE + nitrite 60 ppm (SSN) showed minimum levels of the residual nitrites (13.14 mg/kg), NDMA (0.74 ± 0.05 μg/kg), and biogenic amine (histamine, 1.8 mg/kg; cadaverine, 3.7 mg/kg; and putrescine, 4.3 mg/kg) due to retarded degradation rate of 285.84-216.44 mg/kg; rosmarinic acid, 41.62-33.16 mg/kg; carnosol, and 88.70-76.73 mg/kg; carnosic acid over storage time. The first-order kinetic model fitted well for the degradation of rosmarinic acid and carnosol acid in SSN sample. TBA value remained below the threshold limit (0.32 mg kg-1) through 14 days for SSN. Second-order and zero-order reaction models had the best agreement with sausages' PV and TBA values, respectively. After 2 weeks of storage, E. coli and Cl. perfringens counts in the SN120 (sausage containing 120 ppm nitrite) and SSN were significantly lower than the other samples (p < .05), with the values 2.1 and 1.5 log cfu/g for SN120 and 2.2 and 1.6 log cfu/g for SSN formulation. Conversely, oxidation indices, residual nitrites, NDMA, and biogenic amine increased in sausage samples containing PPE extracts (SPN) owing to total degradation of α- and β-punicalagin during storage. The results indicated that SE can be used as potential co-preservative by reducing the levels of required nitrite in food industry.

Shelf life extension of chilled blunt snout bream fillets using coating based on chia seed gum and Oleum ocimigratissimi

The edible active coating is a popular trend for fish preservation. A hybrid coating composed of chia seed gum (CSG) and Oleum ocimi gratissimi (OG) was investigated, aiming to evaluate its ability to extend the shelf life of chill-stored fish. Physiochemical changes such as sensory analysis, color, moisture state, trichloroacetic acid-soluble peptides, total volatile basic nitrogen content, lipid oxidation indicators including peroxide value and thiobarbituric acid reactive substances, as well as microbial indicators including microbial enumeration and microbiota composition about fillets were assessed to evaluate the antimicrobial and antioxidant capacities of OG/CSG coating. The results showed a reduction of 1–2 log CFU/g of microbial enumeration was achieved during storage. The Illumina-MiSeq high throughput sequencing results showed spoilage bacteria Pseudomonas and Shewanella were effectively inhibited (p < 0.05). OG/CSG coating retarded protein degradation, lipid oxidation, water loss, and discoloration at both lower and higher concentrations (0.5% and 1%) compared with the control group (p < 0.05). In the meantime, there were no differences between the initial color of OG/CSG-coated fillets and the control group (p > 0.05), indicating OG/CSG coating did not affect the initial color of fish fillets. Based on sensory characteristics and microbial enumeration, the shelf-life of the control, 0.5% OG/CSG coated, and 1% OG/CSG coated fillets could be suggested as 5, 7, and 9 days, respectively. This study provides a scientific basis for the applicability of OG/CSG coating in fish preservation.

Feeding Flaxseed and Lupins during the Transition Period in Dairy Cows: Effects on Production Performance, Fertility and Biochemical Blood Indices

Flaxseed and lupin seed were offered as an alternative dietary approach in dairy cows, through the partial substitution of soybean meal. Milk production and fertility traits were investigated. A total of 330 animals were allocated into two groups, treated (n = 176) and control (n = 154). From each group, 30 animals were selected for hematological and cytological studies. The experimental feeding period lasted for 81 days (25 days prepartum and 56 days postpartum). The control ration (group C) contained corn, barley, soybean meal, rapeseed cake, corn silage and lucerne hay; whereas, in the treatment group (group T), 50% of the soybean meal was replaced by an equal mixture of flaxseed and lupins. The two rations were formulated to be isonitrogenous and isoenergetic. Milk samples were analyzed for chemical composition, somatic cell count (SCC) content and total colony forming units (CFU). Blood samples were collected, and serum was analyzed for non-esterified fatty acids (NEFA), acute phase proteins (haptoglobin and serum amyloid) and lipid oxidation indices, namely thiobarbituric-acid-reactive substances (TBARS) and catalase activity. To assess polymorphonuclear neutrophils (PMN) numbers, endometrial samples from each cow were collected on days 21 and 42. No difference was recorded between groups in milk yield (p &gt; 0.05). In multiparous cows, NEFA (mMol/L) concentrations were significantly lower in group T than in group C on day 14 (p &gt; 0.009) and on day 42 (p = 0.05), while no difference was detected in the group of primiparous cows. At all time points, serum TBARS and catalase values were similar in both groups (p &gt; 0.05). Multiparous cows in group T expressed the first postpartum estrus and conceived earlier than cows in group C (p ≤ 0.05). Between days 21 to 42 postpartum, the PMN reduction rate was higher in group T animals (p ≤ 0.05). Acute phase protein levels were in general lower in group T animals, and at specific time points differed significantly from group C (p ≤ 0.05). It was concluded that the partial replacement of soybean meal by flaxseed and lupins had no negative effect on milk yield or milk composition, and improved cow fertility; which, along with the lower cost of flaxseed and lupins mixture, may increase milk production profitability.

Chemical characteristics, oxidation and proteolysis in cheese produced from fresh or stored milk subjected to heat treatments

Cheese produced from fresh, stored or heat pretreated (65°C for 15 s) milk subjected to pasteurisation (72°C or 77°C for 15 s) was studied for chemical characteristics and proteolysis after 4 and 21 days of storage. Antioxidant activity was higher in cheese from fresh milk than in cheese from stored and heat pretreated milk. Malondialdehyde content as an index of lipid oxidation increased in cheese made with pretreated and preserved milk than in cheese made with fresh milk. Antioxidant activity and lipid oxidation were not significantly affected by pasteurisation temperature. Proteolysis increased during cheese maturation regardless of milk heat treatments.

Inhibition of benzo[a]pyrene formation in charcoal-grilled pork sausages by ginger and its key compounds.

Ginger and its extracts have been frequently used in food processing and pharmaceuticals. However, the influence of ginger and its key compounds on benzo[a]pyrene (BaP) production in meat processing has not been investigated. The purpose of this study was to explore the effect of application of ginger and its important active ingredients on BaP formation and the mechanism of inhibiting BaP formation in charcoal-grilled pork sausages. The DPPH scavenging (23.59-59.67%) activity and the inhibition rate of BaP (42.1-68.9%) were significantly increased (P < 0.05) with increasing ginger addition. The active components extracted by supercritical carbon dioxide from ginger were identified by gas chromatography-mass spectrometry and 14 representative compounds (four terpenes, two alcohols, two aldehydes, four phenols and two other compounds, totaling 77.57% of the detected compounds) were selected. The phenolic compounds (eugenol, 6-gingerol, 6-paradol and 6-shogaol, accounting for 29.73% of the total composition) in ginger played a key role and had the strongest inhibitory effect on BaP (61.2-68.2%), whereas four other kinds of compound showed obviously feeble inhibitory activity (6.47-17.9%). Charcoal-grilled sausages with phenolic substances had lower values of thiobarbituric acid-reactive substances, carbonyl and diene (three classic indicators of lipid oxidation) (P < 0.05). Ginger and its key compounds could effectively inhibit the formation of BaP in charcoal-grilled pork sausages. Phenolic compounds make the strongest contribution to the inhibition of Bap formation, and the inhibitory mechanism was related to the inhibition of lipid oxidation. © 2023 Society of Chemical Industry.

Chemical Indices and Kinetic Evaluation of β-Sitosteryl Oleate Oxidation in a Model System of Bulk Oil.

Concerns have been raised about the safety and tolerability of phytosterol esters due to their vulnerability to oxidation. Herein, oxidation of the unsaturated fatty acid-phytosterol ester, namely β-sitosteryl oleate, was observed in comparison to native β-sitosterol after accelerated storage at 65 °C for 35 days in a bulk oil model system. Depending on the sterol structure, various chemical indices of lipid oxidation, including hydroperoxide value (HPV), thiobarbituric acid reactive substances (TBARS), p-anisidine value (AnV), and 7-keto derivatives, changed at varying rates in both samples. Such indicators for β-sitosteryl oleate appeared to be obtained at higher concentrations than those for β-sitosterol. The first order kinetic was used to describe the losses of β-sitosteryl oleate and β-sitosterol in bulk oil. It was discovered that the β-sitosteryl oleate (k = 0.0202 day-1) underwent oxidative alteration more rapidly than β-sitosterol (k = 0.0099 day-1). Results indicated that physical structure was the principal factor in the determination of storage stability of phytosterol and its ester. Research on antioxidants and storage techniques can be expanded in order to reduce the oxidative loss of phytosterol esters during storage and improve the safety and tolerability of phytosterol esters.

Effect of feeding carob (Ceratonia siliqua L.) pulp powder to broiler chicken on growth performance, intestinal microbiota, carcass traits, and meat quality

In this study, the influence of a partial substitution of corn with carob (Ceratonia siliqua L.) pulp powder on broiler performance, intestinal microbiota, carcass traits, and meat quality, was investigated. Two dietary treatments were compared: the control group received a diet containing basically corn, soybean meal, and wheat bran for all the breeding periods while the experimental group received the same starter diet as the control group and grower and finisher diets containing 3% and 7% of carob pulp powder, respectively. Growth performance (weight gain, feed intake, and feed conversion ratio), carcass traits, lactic acid bacteria, and total coliforms were determined. Physicochemical parameters, proximate composition, fatty acid profiles, lipid oxidation index, and sensory characteristics of broiler thigh and breast muscles were determined. Dietary supplementation with carob pulp powder did not show an effect (P > 0.05) on growth performance and carcass traits except for slaughter yield and breast relative weight. An increase in sum lactic acid bacteria count and a decrease in total coliforms were observed in the experimental group. No effect (P > 0.05) of dietary carob was observed on pH, cooking losses, ash, mineral, and protein contents in breast and thigh muscles from broilers. However, the experimental diet decreased (P < 0.05) moisture and fat contents in thigh muscles but not in breast muscles. Both muscles from the experimental group of birds exhibited lower palmitic and oleic acids contents, and higher linoleic and linolenic acids levels than those from the control group. Whereas the polyunsaturated fatty acid contents in broiler breast and thigh meat was increased by dietary carob, the concentration of lipid oxidation products decreased in this group. The dietary intervention had no significant effect on the sensory profile of breast and thigh muscles. Thus, carob pulp powder can be applied to broiler diet at 7% as a nonconventional feed with no negative impact on growth performance and carcass traits and to increase the degree of unsaturation with no negative impact on oxidative stability or sensory traits.