The effect of heat treatment on the cholesterol oxides,cholesterol, total lipid and fatty acid contents of processed meat products

The effects of heat treatment on the formation of cholesterol oxides and on alterations of fatty acid composition were investigated in processed meat products. Meatballs (beef), hamburger (beef and Chester), sausage (pork, chicken and Chester) and frankfurter (mixed meat, chicken and Chester) were analysed. There was no cholesterol oxide formation caused by heat treatment of the samples analysed. The fatty acid compositions, calculated as g/100 g sample, showed alterations only between the raw and grilled beef hamburger. Only the cholesterol levels were significantly changed when comparing the raw and grilled pork sausages and the raw and grilled Chester hamburger, the values being lower in the grilled samples. Also, the total lipid contents of grilled beef hamburgers were lower than the values.     

Effect of gender on the meat quality characteristics and chemical composition of kudu (Tragelaphus strepsiceros), an African antelope species

The kudu (Tragelaphus strepsiceros), one of Africa’s most majestic antelope species, shows a strong sexual dimorphism. The male reaches a larger size (≈250 kg live weight) than the female (≈180 kg live weight). Kudu occur throughout the savannah regions in central Africa, south of the equatorial forests, through East Africa to Ethiopia, Sudan and Chad down to the Eastern Cape (South Africa). Kudu are predominantly browsers, but will occasionally graze. Within South Africa, this species is hunted regularly for local consumption, and Kudu meat is also a regular item in most restaurants that serve game meat and is also frequently exported. However, very little data has been published pertaining to the muscle chemical composition and other quality attributes of its meat. In the present investigation, the proximate, amino acid, fatty acid and mineral chemical compositions of the Longissimus dorsi et lumborum muscle of 18 animals are presented, and the effect of gender thereupon tested by means of standard student’s t-tests. Kudu meat has a high protein and a low fat content. Only two of the longer chained polyunsaturated fatty acids (C20:3n−6 and C20:5n−3) differed between the females and males, the latter having a higher concentration each time. Of the kudu muscle’s fatty acids, 37% were saturated, 22% monounsaturated and 41% polyunsaturated. The mean PUFA to SFA ratio (1.12) was well above the recommended 0.45 prescribed by the British Department of Health. The n−6:n−3 PUFA ratio (2.34) was also well below the British Department of Health’s recommended figure of four. Histidine and valine had significantly higher levels in female kudu meat than in male kudu meat. Phosphorus was present at the highest concentrations in both female and male animals. Overall, the chemical composition of kudu meat is not significantly effected by gender.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 3: Fatty acid composition as influenced by age, gender and production region

The effects of age, gender and production region on the fatty acid composition of springbok Musculus longissimus dorsi (LD) were investigated. The major fatty acid of the LD muscle was stearic acid (C18:0), which contributed 23.92–27.02%. Oleic acid (C18:1) represented the largest component (16.33–20.45%) of the mono-unsaturated fatty acids (MUFA). The major n − 6 polyunsaturated fatty acid (PUFA) was C18:2n − 6, which formed 18.77–21.62%, whereas C18:3n − 3 (3.33–4.00%) was the most abundant n − 3 PUFA. The n − 6:n − 3 ratio of the meat varied from 3.02 to 3.35, with an average ratio of 3.2. Polyunsaturated to saturated (P:S) ratios varied between 0.96 and 1.18 and averaged at 1.06. Total MUFA was found to be higher (P < 0.05) in males (20.99%) than females (16.67%). The cholesterol content of the meat varied from 54.45 to 59.34 mg/100 g muscle. Linear correlations between the fatty acid and the intramuscular fat (IMF) content indicated a significant increase in certain saturated and mono-unsaturated fatty acids with increasing IMF content of the meat.     

Fatty acids, cholesterol and protein content of nutria (Myocastor coypus) meat from an intensive production system in Uruguay

This study describes the total lipids, protein and fatty acids in the meat, liver, brain and adipose tissue of five male and five female nutria (Myocastor coypus). The animals were reared on a specialized farm in Uruguay. Total lipid content was between 1.41% and 1.84% in males and females. Total cholesterol content was between 70.1 mg and 72.7 mg/100 g of wet tissue. The protein content was between 19.56% and 22.34% in males and females. No significant differences (P > 0.05) were detected between males and females for total lipid, cholesterol or protein. Total, saturated, monounsaturated and polyunsaturated fatty acid values were higher (P < 0.001) in female than in male thigh muscle. Pectoral muscle had more (P < 0.05) saturated and monounsaturated fatty acids in females than in males. Subcutaneous adipose tissue from females had the highest (P < 0.01) total, saturated and monounsaturated but not polyunsaturated fatty acids while abdominal adipose tissue from males had more polyunsaturated fatty.     

Game and venison - meat for the modern consumer

This review focuses on how game meat from southern Africa and venison that are increasingly being imported into Europe and the US addresses consumer issues as pertaining to production (wild, free range or intensive production) and harvesting methods, healthiness (chemical composition, particularly fatty acid composition), and traceability. Although African game meat species are farmed extensively, deer species are farmed using extensive to intensive production systems. However, the increasingly intensive production of the cervids and the accompanying practices associated with this (castration, velvetting, feeding of balanced diets, etc.) may have a negative impact in the near future on the consumer's perception of these animals. These alternative meat species are all harvested in a sustainable manner using acceptable methods. All these species have very low muscle fat contents consisting predominantly of structural lipid components (phospholipid and cholesterol) that have high proportions of polyunsaturated fatty acids. This results in the meat having desirable polyunsaturated:saturated and n-6:n-3 fatty acid ratios. The South African traceability system is discussed briefly as an example on how these exporting countries are able to address the requirements pertaining to the import of meat as stipulated by the European Economic Community.     

Cholesterol oxide, cholesterol, total lipid and fatty acid contents in processed meat products during storage

The effects of storage time on the formation of cholesterol oxides and on alterations in the fatty acid composition of processed meat products manufactured by Brazilian industries were investigated in this study. Cholesterol oxides and cholesterol were determined by HPLC using photodiode array and refractive index detectors. Samples of jerked beef, Italian-type salami, chicken mortadella and Chester mortadella were analysed at 30 day intervals starting at zero time, for 90 days for the mortadella and 120 days for the jerked beef and salami. The mortadellas were stored under refrigeration at 6 °C and the jerked beef and salami at room temperature, but protected from the light. No cholesterol oxides were formed during the storage time in any of the samples. The cholesterol content, the fatty acid composition and total lipid contents showed no significant differences during storage with the exception of the total lipid content of the jerked beef, which varied from 3.5 at zero time to 2.4 g/100 g after 120 days storage.     

Cholesterol oxidation products in irradiated raw meat with different packaging and storage time

The effect of irradiation and packaging conditions on the formation of cholesterol oxidation products (COPs) as well as lipid oxidation products was determined in raw turkey leg, beef, and pork loin meat during 7 days of storage. Ground turkey leg, beef, and pork loin muscles were prepared as patties. The patties were individually packaged either in oxygen-permeable or impermeable bags, irradiated at 0 or 4.5 kGy using a Linear Accelerator, and stored at 4°C. The COPs such as 7-hydroxycholesterol, 7β-hydroxycholesterol, and 7-ketocholesterol were detected in fresh raw meats at 0 day at the level of 10.9 to 49.2 μg/g lipid. After 7 days of storage, other COPs such as epoxides, 20-hyroxycholesterol, and choletanetriol were formed in mainly aerobically packaged and irradiated raw meats. Packaging effect was more crucial on the cholesterol and lipid oxidation than irradiation. In aerobically packaged and irradiated meats, turkey leg muscles had higher COPs value than beef or pork did. COPs and thiobarbituric acid reactive substances (TBARS) values had a strongly positive correlation in turkey leg and pork. But, cholesterol oxidation in beef proceeded in irradiated and aerobically stored samples despite of its low level of TBARS value.     

Meat quality of kudu (Tragelaphus strepsiceros) and impala (Aepyceros melampus): The effect of gender and age on the fatty acid profile, cholesterol content and sensory characteristics of kudu and impala meat

Game meat has distinct sensory characteristics and favourable fatty acid profiles which differ between species. The SFA’s percentage was found to be higher in impala meat (51.12%) than kudu meat (34.87%) whilst the total PUFA was higher in kudu (38.88%) than impala (34.06%). Stearic acid (22.67%) was the major fatty acid in impala and oleic acid in kudu (24.35). Linoleic acid, C20:3n-6 and C22:6n-3 were higher in kudu while C20:4n-6, C20:5n-3 and C22:5n-3 were higher in impala. The PUFA:SFA ratio for kudu (1.22) was higher than for impala (0.73) while impala had a higher n-6 PUFA’s to n-3 PUFA ratio (3.76) than kudu (2.20). Kudu was higher in cholesterol (71.42 ± 2.61 mg/100 g muscle) than impala (52.54 ± 2.73 mg/100 g muscle). Sensory evaluation showed impala had a more intense game aroma and flavour while the initial juiciness of cooked samples of kudu was higher. The results show kudu and impala can be marketed for their unique flavours and aromas as well as being a healthy substitute for other red meats.     

风鹅现有工艺加工过程中品质的变化规律

通过对风鹅现有工艺加工过程中pH值、色泽、盐分含量、水分含量、硫代巴比妥酸还原物(thiobarbituric acidreactive substance,TBARS)值、总氮含量、非蛋白氮含量、游离氨基酸含量和游离氨基酸态氮含量等指标的测定,研究风鹅肌肉中品质变化规律及脂肪氧化和蛋白质水解可能对风味产生的影响.结果表明,盐分含量在加工过程中不断上升,水分含量不断下降;pH值和TBARS值在一定范围内波动;总氮含量、非蛋白氮含量、游离氨基酸含量、游离氨基酸态氮含量变化差异显著,风干结束后风鹅肌肉中蛋白质水解指数约为3.8％,游离氨基酸含量占非蛋白氮含量的78％以上,含量最多的游离氨基酸含量为Arg、Thr、Glu、Leu和Ala等,而增加较多的游离氨基酸含量是Asp、Leu、Tyr、Val、Ile和Lys等,大部分游离氨基酸的含量都超过其阈值很多倍,可能对风鹅的风味产生重要影响.     

Hydroperoxide formation in different lean meats

Peroxide is one of the compounds that are indicated to be toxic in the human digestion system. Lean fresh meat samples were collected from beef, lamb, pork and chicken to investigate their hydroperoxide formation potential. Total peroxides of fresh comminuted raw meat were determined by analysing protein-bound peroxides and hydroperoxide compounds in water–methanol and chloroform extracted phases. The amount of total peroxides was ranked as: beef > pork > lamb > chicken. Hydroperoxide formation was examined at different pH values and at different incubation times, using beef and chicken samples. All peroxides were transient, with a maximum value after 2–4 h of incubation at 37 °C. When pH fell from 7 to 1.5, the different peroxides fell by 10–20%. Non-polar peroxide formation could largely (70%) be described by variation in fatty acid composition and hemin content of the meat, while protein-bound peroxide variation was less explained by these variables. Liposome addition increased (40%) the amount of protein-bound peroxides.     

Influence of type of muscles on nutritional value of foal meat

The effect of type of muscle on nutritional characteristic (fatty acid profile, amino acid content, cholesterol and major and minor mineral) of foal meat was investigated. Six muscles: longissimus dorsi (LD), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF), triceps brachii (TB) and psoas major & minor (PM) from twelve foals slaughtered at 15 months from an extensive production system in freedom regimen were extracted for this study. Horse meat is characterized by low fat, low cholesterol content, rich in iron and in vitamin B. Statistical analysis showed that the cholesterol content did not show significant differences (P > 0.05) among muscle with mean value range between 0.62 and 0.57 mg/100 g. Most fatty acid presented significant differences (P < 0.05) with respect to the type of muscle. The obtained results showed that except for the polyunsaturated linoleic acid, the highest contents of fatty acids were found in the hindquarter muscles. Regarding amino acid profile, significant differences (P < 0.05) were observed among muscles and our results indicated that, 100 g of foal meat covered from 80.6 to 86.7% for the daily requirement for an adult man weighing 70 kg for essential amino acids for ST and LD muscles, respectively. Statistical analysis showed significant differences (P = 0.050) for the EAA (essential amino acids) index, which was highest for TB muscle, followed by BF and SM muscles, while the lowest values were reported by ST muscle. Finally, foal meat seems to be a very good nutritional source of major and minor minerals. The higher nutritional value of foal meat will be of great importance in the promotion of this meat.     

Analysis of lipid classes and the fatty acid composition of the salted fish roe food products,Ikura, Tarako,Tobiko and Kazunoko

This study was designed to clarify the content of lipid classes and the fatty acid composition of total lipids (TL), sterol esters (SE), triacylglycerols (TG), phospholipids (PL), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) of the Japanese fish roe products, Ikura, Tarako, Tobiko and Kazunoko. The TL, total cholesterol, TG, and PL content of Ikura were higher than those of Tarako, Tobiko and Kazunoko. Kazunoko had the lowest cholesterol content among these roe products. PC was the main component in the PL class of each fish roe product. The main fatty acids of all roe products were 16:0, 18:1n−9, 20:5n−3, and 22:6n−3. Docosahexaenoic acid (22:6n−3) was rich in the TL, SE, TG, PL, PC and PE fractions of all roe products. In particulars the 22:6n−3 percentage of PC and PE fractions in Tobiko were higher than those of Ikura, Tarako and Kazunoko. These results indicate that the lipid from fish roe products may be a useful food source for maintaining human health.     

不同蛋白质含量大豆结瘤特性与根瘤氮代谢物含量的比较分析

为了明确高蛋白野生大豆氮素积累规律,本试验选取3类不同蛋白质含量的大豆材料,在各生育期对根瘤生长特性及根瘤氮代谢物的含量变化进行研究,结果表明：籽粒蛋白质含量与R2～R8时期的根瘤数呈显著正相关。V6～R2期高蛋白野生大豆根瘤数增加较快,整个生育期根瘤重不断增加。三种类型大豆的血红蛋白含量、单株血红蛋白总量在R2～R8期与籽粒蛋白质含量呈显著正相关。在V6到R8期高蛋白野生大豆血红蛋白含量、总量都明显高于其它两种类型大豆材料,差异性均达到显著水平。R2～R8期三种类型大豆游离氨基酸含量、酰脲含量均呈下降趋势,高蛋白野生大豆游离氨基酸含量低于、而酰脲含量却又高于其它两种类型材料,且差异性显著。说明高蛋白野生大豆根瘤衰老较慢、根瘤内氮代谢物含量丰富,生育后期仍具有较强的酰脲合成与运输能力是形成该类型大豆籽粒高蛋白质含量的原因之一。     

Effects of different levels of trans fatty acids and oxidised lipids in diet on cholesterol and cholesterol oxidation products formation in rabbit

The objective was to assess the effects of trans fatty acids and oxidised lipids, present in dietary fat by-products used in feeds, on cholesterol and oxycholesterols in meat, liver and plasma of rabbits. A palm fatty acid distillate, before and after hydrogenation (trans fatty acid trial), and a sunflower–olive oil blend (70/30, v/v), before and after use in a commercial frying process (oxidised lipid trial), were used in experimental feeds (at 3%, w/w). High trans fatty acid and oxidised lipid diets caused significantly higher cholesterol and oxycholesterol levels in all tissues of rabbit (0.01 < p ? 0.05). The content of oxycholesterols in rabbit meat, liver and plasma obtained from trans fatty acid experiments varied from 9 to 34 μg/100 g, 24 to 61 μg/100 g and 60 to 138 μg/dl, respectively, from low to high levels. In the oxidised lipid experiments, content of oxycholesterols varied from 16 to 52 μg/100 g, 14 to 108 μg/100 g and 52 to 269 μg/dl in meat, liver and plasma, respectively. As a consequence, meat products from rabbits fed a diet containing higher levels of trans fatty acids or oxidised lipids may result in higher intakes of cholesterol and oxycholesterols by humans.     

叶蛋白酶促水解物营养价值的研究

本文通过木瓜蛋白酶对叶蛋白的酶促水解作用来改善叶蛋白功能方面的缺陷，并通过游离氨基酸的测定与实验动物的生长代谢试验来评价其营养价值，研究表明：酶解产生多肽的同时大量的游离氨基酸被释放出来，赖氨酸、苏氨酸、亮氨酸、异亮氨酸、色氨酸这几种必需氨基酸含量有明显的提高；大鼠的生长代谢试验表明：叶蛋白多肽的各项营养指标与未水解的叶蛋白相比有明显差异，并接近酪蛋白。     

Nutritional value of cooked offal derived from free-range rams reared in South Africa

Nutritional value of Dorper (n = 10) and Merino (n = 10) by-products were evaluated. Proximate composition differed between organs and breeds with Merino heart (68.9 g/100 g), spleen (77.2 g/100 g) and testicles (83.7 g/100 g) having higher moisture contents than their Dorper counterparts. Dorper brain (10.1 g/100 g), heart (15.2 g/100 g), spleen (20.4 g/100 g) and testicles (12.9 g/100 g) had higher protein contents than Merino. Dorper organs also tended to have a lower fat content. Amino acid and fatty acid profiles differed between organs and breeds. Few differences were noted in total SFA and MUFA. Dorper heart (1.8%) had significantly lower total PUFA than Merino heart (7.3%). All the organs showed favourable P:S ratios, with the exception of the tongue, heart and stomach. Dorper and Merino brain, lungs and testicles had favourable n − 6/n − 3 ratios. Cholesterol content differed between both organs and breeds. The value of offal as food is discussed further.     

自然发酵肉制品中乳酸菌的分离及特性研究

以MRS和改良TJA(改良番茄汁琼脂培养基)培养基为基础培养基,从自然发酵肉品中分离得到8个菌株,其中4株为乳酸菌,3株为杆菌,1株为球状菌。进一步测试表明:4株乳酸菌在30℃培养时,生长最好;在pH3.5～4.0时生长良好;4株乳酸菌在10%NaCl的环境中均能生长,其中以2%～6%的NaCl浓度内生长最适宜;属兼性厌氧菌;对大肠杆菌产生一定的抑制作用。分离出的4株乳酸菌均适宜作为发酵肉制品的发酵剂。     

What are the potential strategies to achieve potentially more healthful meat products?

In recent years, much attention has been paid to the consumption of meat and processed meat, and their relationship with a healthy diet. This review provides an overview of the potential strategies, which can be used to provide the implications for producing healthy, wholesome and consistently high-quality meat products. Genetic selection, nutrition and feeding management, and gene manipulation techniques have been used as the main strategies to induce beneficial changes in meat and meat composition. Besides, the incorporation of ingredients that play a technological role and are potentially health-enhancing, such as fibre, fat substitutes, natural antioxidants and the reduction of sodium and nitrites, has a high potential in the development of healthier meat products. In this review, we have observed that many strategies have been successfully used to obtain products with low fat, reduced sodium and nitrite content, low cholesterol and absence of synthetic antioxidants. Another point to be highlighted is that some of these strategies also allow obtaining products with positive health effects that can be potential alternatives to improve consumer acceptance.     

甘南牦牛肉质特性和营养成分分析

用常规方法测定甘南藏族自治州牦牛肉中肉质特性和营养成分。结果表明：与当地黄牛肉(对照组)比较,牦牛肉(实验组)干物质高23.19%、蛋白质高6.14%、灰分高12.5%、脂肪低13.54%、氨基酸总量(TAA)高13.38%、必需氨基酸(EAA)高10.88%,必需氨基酸与非必需氨基酸(EAA/NEAA)的比值为67.94%。甘南牦牛肉具有色泽深红、系水力高、熟肉率高、蛋白高、脂肪低、氨基酸种类齐全等特点。     

腌腊肉制品中乳酸菌的筛选鉴定及其在腊肠中的应用

为筛选适合传统腌腊肉制品的优良乳酸菌菌株,从多种农家自制传统腌腊肉制品中分离纯化出9株优势乳酸菌。通过发酵特性筛选,得到一株性状优良菌株10M-7,并制备该菌株的干粉发酵剂,以未接种发酵剂腊肠为对照,分析此发酵剂对腊肠感官品质和微生物变化的影响。结果表明,10M-7菌株具有良好的产酸特性和抑菌性能。根据形态学、生理生化特征和16S rRNA序列分析,鉴定其为植物乳杆菌,采用冷冻干燥法制备纯种发酵剂,并制作人工发酵腊肠。发酵剂组pH值在初期便迅速下降,且始终低于对照组;发酵剂组乳酸菌迅速生长繁殖,且葡萄球菌和大肠杆菌数量与对照组相比明显降低。感官评价表明,当添加量为10~4CFU/g原料肉时,能够很好地保持和改善产品风味,使产品整体感觉更好。