Evaluation of cholesterol and lipid oxidation in raw and cooked minced beef stored under oxygen-enriched atmosphere

Cholesterol Oxidation Products: Potential Adverse Effect and Prevention of Their Production in Foods

Cholesterol oxidation products (COPs) are a group of substances formed during food processing. COPs in diet is a health concern because they may affect human health in association with the risk of various diseases including atherosclerosis, Alzheimer's disease, age-related macular degeneration, diabetes, and chronic gastrointestinal inflammatory colitis. Production of COPs in foods can be affected by many factors such as temperature, pH, light, oxygen, water, carbohydrates, fatty acids, proteins, and metal cations. The key issue is preventing its generation in foods. Some COPs can also be produced in vivo by both nonenzymatic and enzymatic-catalyzed oxidation reactions. Currently, a number of natural antioxidants such as catechins, flavonoids, and other polyphenols have been proven to inhibit the generation of COPs. In addition, measures taken during food processing can also minimize the production of COPs, such as the Maillard reaction and marinating food with plant polyphenol-rich seasonings. In conclusion, a comprehensive approach encompassing the suppression on COPs generation and implementation of processing measures is imperative to safeguard human health against the production of COPs in the food chain.

Effect of olive leaf extract marination on heterocyclic aromatic amine formation in pan-fried salmon

BACKGROUND

In this study, the reducing effects of varying levels of olive leaf extract (0%, 0.25%, 0.5%, 1% and 2%) on the formation of heterocyclic aromatic amines (HAAs) in pan-cooked salmon at 180 and 220 °C were examined.

RESULTS

All salmon samples were analyzed for ten HAAs: IQx, IQ, MeIQx, MeIQ, 4,8-DiMeIQx, 7,8-DiMeIQx, PhIP, AαC, MeAαC and Trp-P-2. The most abundant HAA was MeIQ (≤2.98 ng g^-1 ) followed by Trp-P-2 (≤2.40 ng g^-1 ), MeIQx (≤0.83 ng g^-1 ), IQ (≤0.41 ng g^-1 ), 7,8-DiMeIQx (≤0.29 ng g^-1 ), 4,8-DiMeIQx (≤0.16 ng g^-1 ) and IQx (≤0.06 ng g^-1 ). However, PhIP, AαC and MeAαC were undetectable in all samples. In the control samples, HAAs were found at levels ranging from not detected to 2.40 ng g^-1 . Total HAA content was between 0.81 and 4.03 ng g^-1 . The olive leaf extracts reduced the total HAA levels at all certain concentration levels at 180 °C and the reducing effects were found to be 32.78-77.69%.

CONCLUSION

The current study displayed that olive leaf extracts could be efficient when added in up to 1% concentration prior to cooking for reducing HAA formation without changing organoleptic characteristics of salmon. © 2021 Society of Chemical Industry.

Quality characteristics of the enhanced beef using winter mushroom juice

This study investigated the quality properties of enhanced beef, manufactured by injecting the beef with a brine containing winter mushroom juice powder (WMJP). The enhanced beef was manufactured by injecting the eye of round with brine (15% by green weight). Four treatments consisted of control (no injection of brine) and three enhanced beef, EBS (brine containing 5 g sodium chloride per kg beef), EBW 0.2 (brine containing 5 g sodium chloride and 2 g WMJP per kg beef), and EBW 0.5 (brine containing 5 g sodium chloride and 5 g WMJP per kg beef), were tested. The effect of enhancement or WMJP on the quality properties of beef was evaluated during storage at 4°C for 1, 5, and 10 days. Total aerobic bacteria counts between the control and the enhanced beef, and among EBS, EBW 0.2, and EBW 0.5 were not significantly different after any storage period (p > 0.05). The pH of beef was not different between the control and the enhanced beef, and among enhanced beef at 1 and 5 days of storage (p > 0.05). However, it was higher in the enhanced beef than control, and EBW 0.2 and EBW 0.5 had higher pH than EBS after 10 days of storage (p < 0.05). The enhanced beef showed a high total loss at all storage days (p < 0.05). There were no differences in total loss among enhanced beef after any storage period (p > 0.05). The enhanced beef had no consistent differences in L*, a*, and b* values with control during storage, however, EBW 0.5 showed high color stability. The hardness of the enhanced beef was significantly lower than that of the control after 10 days of storage, although the values were lower at all storage stages. EBS 0.5 had the lowest thiobarbituric acid reactive substance (TBARS) value among cooked beef of all treatments at all storage days. The enhanced beef received higher scores in all sensory properties than control, and no negative effect of WMJP was found in the sensory quality of the enhanced beef. The use of winter mushroom juice can result in quality improvement in enhanced beef.

Effects of n-3 and n-6 feeding sources on the quality and lipid oxidation of meat from feedlot-finished Bos indicus steers

This study was conducted to evaluate the fatty acid profile, sensory properties and lipid oxidation of meat on retail display (RD) from Nellore steers (n = 96) fed diets containing soybean (SOY), sunflower (SUN), or linseed (LIN) oil or a control diet (CON). After slaughtering, samples of the Longissimus muscle were collected for sensory properties (1 day), fatty acid composition (1 day) and oxidation stability (3 days under RDC) evaluations. No differences in total lipids, cholesterol, TBARS, and total SFAs, MUFAs, PUFAs, and PUFA/SFA were observed. However, meat from animals fed vegetable oil had more CLA than that of the CON samples. The flavour, juiciness and overall acceptability were affected by the treatments (P < 0.05), but no consistent effect of a specific oil source was observed. Meat colour was not affected by diets or days under RD, and 7-ketocholesterol was not detected in any sample. The oil sources used in this work were not effective in consistently changing meat properties.

The effect of using different types and rates of onion-water extract in meatball production on the formation of heterocyclic aromatic amines

BACKGROUND

The effect of using different types (yellow, white and purple) and rates (0.25%, 0.50% and 0.75%) of onion-water extract in meatball production on the various quality criteria of meatballs and the formation of heterocyclic aromatic amines (HCAs) was investigated.

RESULTS

It was determined that cooking process caused a reduction in the water content of meatballs as well as an increase in pH values. MeIQx, 7,8-DiMeIQx, 4,8-DiMeIQx, PhIP, AαC and MeAαC could not be detected in any of the analyzed meatballs, while IQx, IQ and MeIQ were determined in some of the samples.

CONCLUSION

The use of 0.25% and 0.50% white onion-water extract in meatball preparation inhibited the formation of IQx and IQ that were identified in the control group, but their quantities could not be determined. However, the use of water extract of varying types of onions in meatball preparation increased the total HCA content due to the increase of the MeIQ formation. In addition, it was determined that as the rate of onion-water extract for varying types of onions increased, the total HCA amount also increased. The total HCA amount of the meatballs varied between 0.05 and 0.1 ng g^-1 . © 2019 Society of Chemical Industry.

Improved Analytical Method for Determination of Cholesterol-Oxidation Products in Meat and Animal Fat by QuEChERS Coupled with Gas Chromatography-Mass Spectrometry

Cholesterol is widely present in animal fats and meat products and can undergo oxidation to form cholesterol-oxidation products (COPs) during heating. The objective of this study was to develop a QuEChERS method for the determination of COPs in edible animal fats and meat products via gas chromatography-mass spectrometry in which the required solvent volume and extraction time were reduced. By employing a DB-5MS capillary column (30 m × 0.25 mm i.d., 0.25 μm film thickness) and a temperature-programming method, seven COPs, cholesterol, and the internal standard 5α-cholestane could be separated within 19 min. The limits of detection and limits of quantitation based on the COP standards ranged from 0.16 to 180 ng/mL and from 0.32 to 400 ng/mL, respectively, and the recoveries ranged from 89.1 to 107.6% for boiled pork and from 80.5 to 105.6% for lard. The intraday variabilities for boiled pork and lard ranged from 2.27 to 6.87% and from 1.52 to 9.78%, respectively, whereas the interday variabilities ranged from 1.81 to 7.89% and from 3.57 to 9.26%, respectively. Among the various meat samples, fish showed the highest level of COPs (31.84 μg/g). For the edible fats, the COP contents in tallow (22.79-60.15 μg/g) were much higher than those in lard (0.152-2.55 μg/g) and butter (0.526-1.36 μg/g). Collectively, this method can be applied to determine COPs in cholesterol-containing foodstuffs.

An overview of Jatropha curcas meal-induced productive and reproductive toxicity in Japanese quail: Potential mechanisms and heat detoxification

The present study was carried out to investigate the toxic effects of dietary inclusion of raw Jatropha cucas meal [RJM, 3.5%] on productive and reproductive performances of laying Japanese quail and the influence of physical treatment of jatropha meal by heating at [100 ^oc] for 24 or 48 h [JH₂₄ or JH₄₈ respectively] on reducing these effects. The inclusion of RJM in quail diets significantly decreased the egg production, fertility and hatchability percentages and resulted in a high mortality rate. While heat-treated jatropha meal [JH₂₄ or JH₄₈] improved such undesirable effects. The levels of hepatic proteins related to lipid synthesis, cholesterol metabolism and those related to lipid synthesis and transporting to egg yolk were increased in JH₂₄ and JH₄₈ groups than RJM group. Hepatic contents of vitellogenin [VGT-II] and estrogen receptor α [ERα] and circulating estradiol [E2] were improved in JH₄₈ than RJM and JH₂₄ groups however still under the control values. On the other hand, estrogen receptor β [ERβ] were restored to normal control value in both JH₂₄ and JH₄₈ groups. Histopathological investigation revealed that RJM produced various alterations in the histoarchitecture of liver, ovary and oviducts but these alterations were reduced in both JH₂₄ and JH₄₈ groups. From the obtained data we concluded that heating of jatropha meal for 24 h improved its nutritive value and increasing the time of heating is preferable for reduction of the most of toxic impacts indicating that heat treatment can convert toxic jatropha meal to an alternative protein source for livestock feed in a cheap and clean way without combining any other types of treatments.

Improved Oxidative Stability of Enhanced Pork Loins Using Red Perilla Extract

Enhanced meat is defined as fresh meat that has been minimally processed to improve quality and consistency. The present work investigated the quality of enhanced pork loins manufactured with the extract of red perilla leaves (ERP). ERP was prepared by the aqueous extraction of red perilla leaves followed by lyophilization. Enhanced pork loins were produced by injecting brine (15% v/w). The treatments consisted of a control (brine containing no ERP), ERP 0.2 (brine containing ERP at a concentration of 2 g/kg of pork loin), and ERP 0.4 (brine containing ERP at a concentration of 4 g/kg of pork loin). The enhanced pork loins were stored at 4℃ for 7 d, and its quality parameters were investigated. Addition of ERP decreased the L*-value and increased the a*- and b*-values of enhanced pork loins compared to those of the control group at all storage intervals (p<0.05). A significantly lower pH than that of the control was found in ERP 0.4 after 7 d of storage. The malondialdehyde contents of the cooked pork loins were significantly lower in ERP 0.2 and ERP 0.4 than in those of the control after 4 and 7 d of storage (p<0.05). While ERP 0.4 received relatively low scores in taste, flavor, and overall acceptability of the cooked pork loins (p<0.05), no significant differences were found between the control and ERP 0.2. Enhanced pork loins can be produced using ERP to improve their oxidative stability.

Impact of Cooking, Storage, and Reheating Conditions on the Formation of Cholesterol Oxidation Products in Pork Loin

This study investigates the effect of cooking, storage, and reheating conditions on the formation of cholesterol oxidation products (COPs) in pork loin. Samples of pork loin procured 24 h postmortem were initially processed and assessed for total fat and cholesterol content. The cooking methods evaluated were pan roasting, steaming, oven grilling, and microwaving. Cooked pork loin samples were stored at 4℃ and reheated after 3 and 6 d of storage using the original method of preparation or alternately, microwaving. Fat content increased significantly with cooking as a result of the loss in moisture but cholesterol content remained unchanged. Pan roasting and microwave cooking caused a significantly higher production of COPs, as with the process of reheating using microwave, pan roasting, and oven grilling methods. The major COPs found in pork loin were cholestanetriol, 20-hydroxycholesterol, and 25-hydroxycholesterol, whose concentrations varied according to the different cooking and reheating methods used. Moreover, the aerobic storage of cooked pork loin under a refrigerated condition also increased the formation of cholesterol oxides on reheating.

Cooking, storage, and reheating effect on the formation of cholesterol oxidation products in processed meat products

BACKGROUND

Cholesterol is an important biological compound; however, its oxidation products have been proven to be harmful to human health. Cooking, storage, and reheating methods significantly affect the safety of meat products, as they contribute to the production of cholesterol oxidation products (COPs).

METHODS

Three cooking methods were used to cook sausages, loin ham, bacon, luncheon meat, and pressed ham, in order to investigate the effect of cooking, storage, and reheating on total cholesterol and on the formation of COPs. Cooked samples were stored at 4 °C and reheated after 3 and 6 storage days by the same cooking method or by microwaving. The samples were assessed for total lipids, cholesterol, and cholesterol oxides.

RESULTS

The average cholesterol content in the processed meat varied from 76.0 mg/100 g to 201.70 mg/100 g. Microwaved ham showed the lowest cholesterol content compared to that of other processed meat products. Significant differences were found in cholesterol content and cholesterol oxidation products depending on cooking, storage, and reheating methods. Six cholesterol oxides were found in processed meat, of which 7β-hydroxycholesterol and α-epoxides were detected as the major oxidation products.

CONCLUSIONS

Microwaving and oven grilling resulted in higher production of COPs in processed meat as compared with other cooking methods. Refrigerated storage tended to significantly increase the COPs content.

Influence of vacuum skin packaging on color stability of beef longissimus lumborum compared with vacuum and high-oxygen modified atmosphere packaging

The objective of this study was to investigate how color stability of beef is affected by vacuum skin packaging (VSP) compared with vacuum packaging (VP) and high-oxygen modified atmosphere packaging (MAP; 80% O₂ and 20% CO₂). Longissimus lumborum muscles were aged in vacuum for 7 days and then cut into 2-cm-thick slices and repacked using VSP, VP and MAP for another 7 days. Color stability was measured during the next 5 days in air and samples for α-tocopherol and NADH analyses were obtained at the beginning and end of aerobic storage. Color stability, α-tocopherol and NADH of steaks were affected by packaging methods and storage time in air (P<0.05). Higher a* value was obtained in VSP on day 5 compared with VP. Steaks packed in VSP had better color stability than in VP and their color was similar to MAP at the end (day 5) of storage.

Effects of cooking methods and temperatures on nutritional and quality characteristics of anchovy (Engraulis encrasicholus)

The aim of this study was to determine the nutritional and quality characteristics of anchovy after cooking. The fish were cooked by different methods (frying, baking and grilling) at two different temperatures (160 °C, 180 °C). Crude ash, crude protein and crude fat contents of cooked fish increased due to rise in dry matter contents. While cooking methods affected mineral content of anchovy, cooking temperature did not affect. The highest values of monounsaturated fatty acids were found in baked samples. Polyunsaturated fatty acids in baked samples were also high and similar in fried samples. Fried samples, which were the most preferred, lost its nutritional characteristics more than baked and grilled samples. Grilled and baked fish samples can be recommended for healthy consumption. However, grilled fish samples had hard texture due to more moisture loss than other methods. Therefore, it is concluded that baking is the best cooking method for anchovy.

Cholesterol and lipid oxidation in raw and pan-fried minced beef stored under aerobic packaging

BACKGROUND

The type of packaging atmosphere has been reported as a technological factor that consistently affects the quality of lipid fraction in meat. Oxidation of cholesterol and lipids was evaluated before and after pan frying in commercial refrigerated minced beef stored under aerobic atmosphere for 1 and 8 days.

RESULTS

In raw beef, cholesterol and lipid oxidation developed at a slow rate. Cholesterol oxidation products (COPs) did not significantly vary (approximately 8 microg COPs g(-1) of fat) over 8 days, while in the same period thiobarbituric acid reactive substances (TBARS) less than doubled (from 0.7 to 1.2 malondialdehyde equivalents kg(-1) of muscle). Pan frying did not influence the oxidative degree in the fresh product but consistently catalyzed cholesterol oxidation in stored beef. A significant increase was assessed in beef at the end of storage: from 8.6 to 30.0 microg COPs g(-1) of fat in raw and cooked beef, respectively.

CONCLUSION

Aerobic packaging did not appear as a pro-oxidant factor in fresh minced beef with a good oxidative quality during a short period of refrigerated storage.