Inhibition of lipid oxidation and dynamics of polyphenol content in mechanically deboned meat supplemented with sea buckthorn (Hippophae rhamnoides) berry residues

Mechanically deboned meat (MDM) contains about 10 times more polyunsaturated fatty acids (PUFAs) and also more hemoproteins than hand deboned meat (HDM) and is essentially more susceptible to both chemical and biochemical oxidation. The oxidation, leading to the formation of potentially mutagenic and carcinogenic derivatives of PUFAs, can be inhibited by berry extracts rich in antioxidant polyphenols. Using the 2-thiobarbituric acid reactive substances (TBARS) method, we have established that the ethanol slurry of the juice-free solid residue of sea buckthorn (Hippophae rhamnoides – SB) berries inhibits oxidation of unsaturated fatty acids, of both chicken and turkey MDM. The polyphenols, mainly flavonols, responsible for this inhibition, are comparatively stable during short-term cooking and 6-day storage of cooked SB-MDMs at +6 °C. About half of the polyphenols are lost, obviously oxidised, during the storage of the uncooked samples of turkey 2%SB-MDM at +6 °C. The loss of polyphenols is much smaller in the case of chicken MDM, which is characterised by an in situ lower content of fatty acids, including the polyunsaturated ones. The liquid chromatography–diode array detection–tandem mass spectrometry (LC–DAD–ESI-MS/MS) method was used for identification and ranking of the potent polyphenolic antioxidants in the berry residue.     

Anti-oxidant activity of added tea catechins on lipid oxidation of raw minced red meat, poultry and fish muscle

The comparative anti-oxidative effects of added tea catechins (TC) and α-tocopherol to raw minced red meat (beef and pork), poultry (chicken, duck and ostrich) and fish (whiting and mackerel) muscle on susceptibility to lipid oxidation were investigated during 10 days of refrigerated (4 °C) display. Fresh meats, poultry and fish, purchased from a local market, were trimmed to remove bones, skin and surface fat and minced through a 4 mm plate. The minced muscle of each species was treated with either the addition of 300 mg TC kg^–1 minced muscle (TC300) or 300 mg α-tocopherol kg^–1 minced muscle (VE300). Minced muscle without any additives served as control (C). Oxidative stability (TBARS) was measured at 3-day intervals. Total lipids, fatty acid composition, total iron and haem iron from minced muscle for each species were also analysed. The susceptibility of untreated minced muscle to lipid oxidation was in the decreasing order: mackerel > beef > duck > ostrich > pork ≥ chicken > whiting. This may be because of the different content of total fat, iron and fatty acid composition between species. The TC300 significantly ( P  < 0.05) reduced lipid oxidation compared with controls for all seven species as shown by lower TBARS values. The anti-oxidant potential of TC was two to fourfold greater than that of α-tocopherol at the same concentration and this potential was species dependent. The VE300 showed limited capacity in inhibiting lipid oxidation for pork, chicken, duck and whiting. The results obtained show that TCs are powerful natural antioxidants when used in minced muscle food.     

Preparation and in vitro antioxidant activity of enzymatic hydrolysates from oyster (Crassostrea talienwhannensis) meat

Oyster is an abundant resource from ocean, which contains high content of protein. In the present study, oyster (Crassostrea talienwhannensis) meat was digested with three proteases including papain, neutrase and alcalase respectively and the derived hydrolysates were fractionated using a series of ultrafiltration membranes (molecular weight cut‐offs of 10, 5, 3 and 1 kDa). The resultant peptide fractions were evaluated for antioxidant activity using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay and reducing power assay. Results indicated that oyster meat hydrolysates (OMHs) possessed DPPH radical scavenging capacity and reducing power in a dose‐dependent manner. The fractions below 1 kDa showed the strongest overall antioxidant activity. The present study demonstrated that the antioxidant potent of OMHs was strongly related to their concentration, size and amino acid composition.     

Effect of phosvitin on lipid and protein oxidation in ground beef treated with high hydrostatic pressure

In this study, we aimed to examine the effect of phosvitin on lipid and protein oxidation of raw and cooked ground beef treated with high hydrostatic pressure (HHP). Ground beef patty with 0, 500, or 1000 mg phosvitin/kg meat was treated with HHP at 0.1, 300, or 600 MPa. Half of the patties were used in a raw meat analysis, and the other half were used in a cooked meat analysis. Phosvitin and HHP treatment at 300 MPa synergistically reduced microbial growth, and HHP treatment at 600 MPa reduced microbial counts to undetectable levels (< 1 log CFU/g) throughout the length of the study in all samples. Phosvitin delayed lipid and protein oxidation in HHP-treated cooked and raw ground beef, respectively. However, phosvitin had no effect on the color changes of raw ground beef attributable to HHP. The results indicated that phosvitin could enhance the stability of lipids and proteins but not color changes of raw ground beef caused by HHP.     

Synchronised interrelationship between lipid/protein oxidation analysis and sensory attributes in refrigerated minced beef meat formulated with Punica granatum peel extract

Microbiological, chemical and sensory effects of pomegranate peel ethanol extract (EE) at 0.1, 0.5 and 1% (w w⁻¹) on refrigerated minced beef meat were undertaken. Chemical analyses revealed that the treated meat underwent significant decrease (P < 0.05) of primary and secondary lipid oxidation. By the end of storage, EE at 1% reduced the MetMb, carbonyl group accumulation and the disappearance of sulphydryl proteins by 56.68, 65.71 and 59.69% respectively, compared with control samples. EE at 1% showed also the highest scores for colour, appearance, odour and overall acceptability (OA) attributes using a 9-point hedonic scale. Chemometric approaches showed that lipid/protein oxidation analysis, sensory attributes and storage time allowed the samples discrimination. Oxidative stability parameters were equally used to predict OA by linear regression analysis. The reported data provide an approach to strengthen the interpretation of sensory quality and how they are affected by chemical changes in newly formulated meat products.     

Packaging-specific influence of chitosan on color stability and lipid oxidation in refrigerated ground beef

We examined the influence of chitosan on lipid oxidation and color stability of ground beef stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with chitosan (1%) or without chitosan (control) were packaged either in high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), vacuum (VP), or aerobic packaging (PVC) and stored at 1 °C. Chitosan increased (P < 0.05) redness of patties stored in PVC and CO, whereas it had no effect (P > 0.05) in HIOX. Chitosan patties demonstrated lower (P < 0.05) lipid oxidation than controls in all packaging. Control patties in PVC and HIOX exhibited greater (P < 0.05) lipid oxidation than those in VP and CO, whereas chitosan patties in different packaging systems were not different (P > 0.05) from each other. Our findings suggested that antioxidant effects of chitosan on ground beef are packaging-specific.     

Incorporating essential oils of marjoram and rosemary in the formulation of beef patties manufactured with mechanically deboned poultry meat to improve the lipid stability and sensory attributes

The effect of addition of essential oils of marjoram (Origanum marjorana L.) and rosemary (Rosmarinus officinalis L.) at concentration of 200 mg/kg to beef patties formulated with 200 g/kg mechanically deboned poultry meat (MDPM) was studied. The proximate composition, lipid oxidation, sensory characteristics and microbial counts of beef patties manufactured with 200 g/kg MDPM (percentage of lean portion) were assessed during frozen storage at ?18 °C. Beef patties formulated with MDPM (200 g/kg) showed significant (P < 0.05) reduction in protein content and significant (P < 0.05) increase in fat content. Incorporating MDPM in beef patties formulation significantly (P < 0.05) increased the TBARS (Thiobarbituric acid reactive substance) values and significantly (P < 0.05) reduced the flavor and overall acceptability scores. Addition of essential oils of marjoram and rosemary at level of 200 mg/kg significantly (P < 0.05) reduced the TBARS and significantly (P < 0.05) increased the sensory scores of beef patties during frozen storage period. Overall, the study indicated the potential use of natural herbal essential oils to protect against lipid oxidation and improve the sensory attributes of beef patties formulated with MDPM.     

Effect of selected commercial substances with cryoprotective activity on the quality of mechanically recovered,washed and frozen stored poultry meat

Investigations were conducted on mechanically recovered poultry meat (MRPM) and on protein preparation obtained from MRPM by washing it first with 1% water solution of sodium chloride and with water afterwards. The raw materials were frozen at the temperature of –23°C. The effect of added stabilizers on the quality of gels produced from fresh raw materials, and after freezing and frozen storage was assessed. The following additives were used: 1% pork hydrolizate (Pork Stock( 0.5% Cremodan containing carrageens, and 1.5% bovine blood plasma (AMP 600N). Freezing and frozen storage caused a significant reduction of functional properties of MRPM and its protein preparation. None of the examined additives protected simultaneously all the investigated functional properties of the frozen samples. The amount of thermal drip, the gel texture and the amount of protein transition heat were determined by scanning differential calorimetry. The lowest thermal drip in gels obtained from frozen‐stored samples was observed when bovine blood plasma was used as a stabilizer. On the other hand, the most advantageous protective effect on the proteins of the frozen MRPM and on the preparation, determined by mechanical strain resistance of the gels, was found with 1% pork hydrolizate added. The results of thermodynamic investigations of proteins revealed that the best protective effect on the frozen preparation was observed with 1.5% blood plasma added. No protective activity of added Cremodan on proteins of the frozen protein preparation was noted.     

ACE抑制肽的酶法制备及其构效关系的研究进展

高血压病是目前世界范围的主要慢性疾病之一,血管紧张素转换酶(ACE)对调节血压起着关键性作用,ACE抑制肽可以通过抑制ACE的活性起到降血压作用。因此,寻找天然、安全的食物来源的ACE抑制肽是目前生物活性肽领域的研究热点。综述了近年来在ACE抑制肽的酶解、分离纯化、氨基酸序列的鉴定,以及其构效关系等方面的最新研究结果,并展望了其发展前景。     

Active oxygen scavenging activity of egg-yolk protein hydrolysates and their effects on lipid oxidation in beef and tuna homogenates

Egg-yolk protein hydrolysates were prepared by the enzymic hydrolysis of fat-free egg-yolk protein. The active oxygen scavenging activity, of egg-yolk protein hydrolysates, was investigated using several methods. Egg-yolk protein hydrolysates suppressed discoloration of β-carotene, strongly as compared with the control in β-carotene bleaching method. Superoxide-scavenging activity of egg-yolk protein hydrolysates was measured using the xanthine–xanthine oxidase system. Egg-yolk protein hydrolysates exhibited superoxide-scavenging activity in a dose-dependent manner. Egg-yolk protein hydrolysates also showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical-scavenging activity. At 0.5% of the hydrolysates, DPPH and hydroxyl radical-scavenging activities were 74.2% and 91.7%, respectively. In food model systems, egg-yolk protein hydrolysates effectively inhibited thiobarbituric acid reactive substances (TBARS) formation from ground beef and tuna homogenates. These results suggest that egg-yolk protein hydrolysates are good source of natural antioxidants.     

Grass carp peptides hydrolysed by the combination of Alcalase and Neutrase: Angiotensin‐I converting enzyme (ACE) inhibitory activity,antioxidant activities and physicochemical profiles

In this study, grass carp peptides were prepared by enzymatic hydrolysis of grass carp protein using the combination of Alcalase and Neutrase, and angiotensin‐I converting enzyme (ACE) inhibitory activity in vitro, antihypertensive activity in vivo, antioxidant activities, and physicochemical properties of peptides achieved from grass carp protein were characterised after ultrafiltration and desalted processes using mixed ion exchange resins. The purified peptides exhibited strong ACE inhibitory activity (IC₅₀ = 105 μg mL^?1), antihypertensive activity with the maximal drop for systolic blood pressure (SBP) of 43 mmHg at a dosage of 100 mg per kg body weight in spontaneously hypertensive rat (SHR), and antioxidant activities indicated by thiobarbituric acid‐reactive substance values in a liposome‐oxidising system, radical‐scavenging activity and chelation of metal ions (Fe²⁺). The molecular weight of peptides was <1000 Da. Compared to grass carp protein, the peptides separated from enzymatic hydrolysates possessed similar amino acid compositions, but contained higher concentrations of essential amino acids. Moreover, the peptides exhibited excellent solubility at a wide range of pH values from 2 to 10, and lower apparent viscosity than the protein. The peptides separated from enzymatic hydrolysates might be used as a promising ingredient in antihypertensive functional foods and nutraceuticals.     

Effects of pork meat cut and packaging type on lipid oxidation and oxidative products during refrigerated storage (8 degrees C)

ABSTRACT:  Lipid oxidation and oxidative products as affected by pork meat cut, packaging method, and storage time were evaluated during refrigerated storage. Pork belly had higher pH and thiobarbituric acid reactive substance (TBARS) values than pork loin, and aerobic-packaged belly had higher TBARS than vacuum-packaged counterparts. Loin had higher free fatty acid (FFA) values than belly, and increased FFA values were observed with increased storage time. Peroxide values increased up to 7 d and decreased thereafter. Volatile compounds such as alkanes, aldehydes, ketones, and alcohols with high volatility in belly were higher than those in loin. Nonanoic acid, ethyl ester in belly, and hexadecanoic acid in loin might be considered as indices of lipid oxidation. Overall, vacuum packaging was better than aerobic packaging to retard lipid oxidation and production of oxidative products, and loin was more sensitive to lipid oxidation than belly.     

Finishing steers with diets based on corn, high-tannin sorghum or a mix of both: Color and lipid oxidation in beef

We tested the hypothesis that feeding high-tannin sorghum (HTS) to steers would produce beef more resistant to oxidative deterioration. We observed lower thiobarbituric acid-reactive substances (TBARS) in Gluteus medius of steers fed HTS before it was displayed (P=0.028), which could be explained by a reduced response to stress in these animals. While steers finished with corn and corn+HTS had elevated plasma cortisol at the end of the feeding period (P=0.047 and 0.093, respectively), animals fed HTS and corn+vitamin E did not. However, feeding HTS increased the rate of discoloration and TBARS accumulation after aerobic display of Longissimus lumborum and Gluteus medius. Diet did not affect the activity of oxidation-related enzymes and fatty acid composition of muscle. The accelerated rate of lipid oxidation during display of beef could be partially explained by a numerically lower concentration of tocopherols in the tissue.     

Identification and molecular mechanisms of novel antioxidative peptides from fermented camel milk (Kachchi breed,India) with anti-inflammatory activity in raw macrophages cell lines

The investigation was aimed at assessing anti-inflammatory and antioxidative activities along with the release of peptides with antioxidative properties during the fermentation of camel milk by Lacticaseibacillus casei (NK9). Reverse-phase high-performance liquid chromatography (RP-HPLC) was used to separate the bioactive peptides of 3 and 10 kDa (permeates and retentates). Reverse-phase liquid chromatography–mass spectrometry (RPLC/MS) was used to identify and characterise the pure bioactive peptides, and the effect of fermented camel milk on inflammation produced by lipopolysaccharide (LPS)/endotoxin in RAW 264.7 (Ralph and William's cell line) was also examined. Furthermore, docking revealed that peptides (LLNEK and IYTFPQPQSL) were predicted to inhibit myeloperoxidase (nMPO) activity by engaging with different residues in and around the human myeloperoxidase (hMPO) active site.     

Encapsulated phosphates reduce lipid oxidation in both ground chicken and ground beef during raw and cooked meat storage with some influence on color,pH, and cooking loss

Effects of encapsulated sodium tripolyphosphate (STP), sodium hexametaphosphate (HMP) and sodium pyrophosphate (SPP) on lipid oxidation in uncooked (0, 2, 24 h) and cooked (0, 1, 7 d) ground chicken and beef during storage were determined. Ten phosphate treatments included a control (no phosphate), three unencapsulated (u) at 0.5% and three encapsulated (e) phosphates (0.5%) each at a low (e-low) and high (e-high) coating level. Two heating rates (slow, fast) were investigated. Cooking loss (CL), pH, color, orthophosphate (OP), TBARS and lipid hydroperoxides (LPO) were determined. A fast heating and uSTP resulted in lower CL (p < 0.05). Orthophosphate increased with phosphate incorporation, slow heating and storage (p < 0.05). Encapsulated phosphates and increased coating level reduced OP (p < 0.05). Unencapsulated STP increased CIE a* and pH, whereas uSPP decreased CIE a* and pH (p < 0.05). Encapsulated phosphates and the greater coating level had no effect on the pH in cooked samples. Not increased coating level but encapsulated phosphates decreased lipid oxidation in cooked samples (p < 0.05).