Lipolysis, proteolysis, physicochemical and sensory characteristics of different types of Spanish ostrich salchichon

The objective of this study was to compare three different types of salchichon: made of ostrich meat, made of ostrich meat and lean pork, and made of ostrich meat and pork belly, from physicochemical and sensory viewpoints. To evaluate the intensity of lipolysis and proteolysis produced during the ripening process, the profile and content of free fatty acids, the degree of rancidity, the non-protein, water-soluble and aminoacidic nitrogen content were determined. In addition, the composition of the fermented sausages (pH, a_w, moisture, fat, protein, ash, sodium chloride and sodium nitrite content) was analysed. From a sensory viewpoint, the organoleptic characteristics of the different types of salchichon were studied using free choice profiling. The fermented sausages had varying characteristics depending on their formulation (ostrich meat or ostrich meat plus pork) and all of them were well accepted by the panelists. This study helps characterise the different types of ostrich salchichon made in Spain.     

Quality characteristics of ostrich (Struthio camelus) burgers

Quality characteristics and storage stability of three types of burgers prepared with ostrich meat (alone or mixed with pork or beef meat) were evaluated. Burger evaluation was based on chemical, microbiological, textural, colour, sensory and oxidation characteristics. All of the assayed formulas showed acceptable general quality scores in the sensory evaluation, but the burgers formulated with 100% ostrich meat or mixing ostrich and beef meat had the highest scores. Only TBA values and redness were influenced by storage time. Burgers formulated with ostrich and pork meat had a faster oxidation rate and became more oxidized than the others. Microbial counts indicated that, at the end of the refrigerated storage (9days), all of the preparations were spoiled.     

Physicochemical and microbiological characteristics of biltong,a traditional salted dried meat of South Africa

The microbiological and physicochemical characteristics of several commercial beef, kudu and springbok biltong samples from South Africa were assessed in this study. Analysis of samples allowed their differentiation into ‘dry’ and ‘moist’ samples. Dry biltong showed low moisture content (21.5–25.3 g/100 g), a low water activity (0.65–0.68) and a high salt content (5.5–7.9 g/100 g), while moist biltong showed a higher moisture content (35.1–42.8 g/100 g), a higher water activity (0.85 to 0.89) and a lower salt content (3.8–5.6 g/100 g). The pH value did not vary significantly between both groups (5.00–6.26). The results showed that dry biltong presented a low total plate count (TPC) content, a high level of lactic acid bacteria (LAB) and a high level of d-lactic acid as compared to moist biltong. These results suggest that dry biltong complies with the standard hygienic quality (TPC < 7 log cfu/g in agreement with the Food Standards Agency), while moist biltong samples generally showed a low content of d-lactic acid and a low ratio LAB/TPC.     

Cholesterol content and fatty acid composition of ostrich meat as influenced by subspecies

Two muscles, the m. gastrocnemius and m. iliofibularis, were excised from the left legs of six Red Neck (Struthio camelus massaicus) and six Blue Neck (Struthio camelus australis) ostriches and analysed for lipid and cholesterol content and fatty acid composition. Total lipid (1.43 g 100g ) and cholesterol content (65.63 mg 100g ) did not differ (ps> 0.05) in any muscle between subspecies. Although the percentage of some individual fatty acids differed (p < 0.05), the total percentage of saturated fatty acids and total monounsaturated fatty acids was similar (p > 0.05) between subspecies in both muscles. Although the percentage total polyunsaturated fatty acids was higher (p < 0.05) in Blue Necks (23.78%) than in Red Necks (23.65%) in the m. gastrocnemius, but not (p > 0.05) in the m, iliofibularis, the difference of 0.13% is probably of no practical significance.     

Meat quality characteristics of springbok (Antidorcas marsupialis). 2: Chemical composition of springbok meat as influenced by age, gender and production region

The effects of age, gender and production region on the chemical, mineral and amino acid composition of the M. longissimus dorsi (LD) muscle of springbok were investigated. There was a significant gender^*region interaction for protein content – for the four production regions it varied between 18.80 and 21.16 g/100 g. The intramuscular fat (IMF) content of the LD muscle varied between 1.32 and 3.46 g/100 g. Females (3.13 ± 0.28 g/100 g) had a higher (P < 0.05) fat content than males (1.35 ± 0.08 g/100 g). The IMF content of the adult (2.45 ± 0.26 g/100 g) and sub-adult (2.50 ± 0.28 g/100 g) categories was higher (P < 0.05) in comparison to that of the lambs (1.32 ± 0.11 g/100 g). An inverse correlation was noted between the IMF and moisture content (r = −0.49, P < 0.001) of the meat. The two main amino acids were glutamic and aspartic acid, which contributed 2.47–2.74 and 2.31–2.54 g/100 g of dry matter, respectively. Phosphorous was the predominant mineral in the LD muscle (122.92–159.78 mg/100 g of dry matter), followed by potassium (119.44–131.25 mg/100 g of dry matter) and calcium (6.57–145.18 mg/100 g of dry matter). Production region had a significant effect on the mineral and amino acid composition of the meat, while the effects of age and gender were found to be insignificant.     

Physicochemical and sensory properties of chicken nuggets with washed mechanically deboned chicken meat: Research note

The effects of different proportions (0%, 10%, 20%, 30%, 40%) of washed mechanically deboned chicken meat (WM) as a substitute for hand deboned chicken meat, on the physicochemical and sensory characteristics of chicken nuggets were evaluated. The addition of WM increased fat content, but it was only significant (P < 0.05) when 40% of WM was added, whereas the protein content was significantly (P < 0.05) reduced as from 20%. Significant differences (P < 0.05) were found in L^*, a^* and b^* values with different proportions of WM, however, these differences were evidently not discerned as shown by the no significant differences (P > 0.05) in ΔE^* color scores. The addition of WM did not affect (P > 0.05) sensory attributes of chicken nuggets. From a technical viewpoint, up to 40% WM could be incorporated into nugget formulation instead of hand deboned chicken meat without affecting sensory attributes of the product. Minor changes in composition were observed but they were probably not detrimental to the product.     

Proximate,amino acid and mineral composition of ostrich meat

The proximate composition, amino acid composition and mineral composition of three different muscles from the legs of seven ostriches were determined. Results indicated that components analyzed remained relatively constant between different muscles. Ostrich meat is characterized by an extremely low intramuscular fat content. Values for water, protein, ash, amino acid and mineral contents are in agreement with values obtained for beef and chicken.     

Physicochemical and sensory characteristics of restructured beef steak with added walnuts

The effects of different proportions (0, 5, 10, 15%) of added walnuts on the physicochemical and sensory characteristics of restructured beef steak were evaluated. The addition of 10 and 15% walnut reduced (P<0.05) cooking loss. Increasing proportions of walnut in the beef steak increased (P<0.05) water binding and reduced (P<0.05) fat binding properties. The addition of walnut did not affect (P>0.05) textural properties in uncooked restructured beef steak, but in cooked products Kramer shear force and bind strength were reduced (P<0.05) when 10% or more of walnut was added. Product morphology characteristics suggest that walnut interferes with the formation of protein network structures. Restructured steaks made with added walnut presented acceptable sensory properties. Incorporation of nuts in meat products can be use to confer potential heart-healthy benefits (Spanish Patent Application 200300367).     

Physicochemical Characterization of the Strawberry Samples on Regional Basis Using Multivariate Analysis

Six strawberry samples, commercially grown in Pakistan, were studied for physicochemical properties. All samples have high level of water and low contents of ash and volatile compounds. The berry was found to be a good source of potassium (1.14–1.93 g/kg), magnesium (0.12–0.15 g/kg), calcium (79.59–124.11 mg/kg) and sodium (23.51–36.03 mg/kg). The lead and cadmium contents were below the detection limits (1.0 ± 0.1 μg/l for lead and 0.1 ± 0.01 μg/l for cadmium). Principal component analysis and cluster analysis were found to be good statistical tools for the evaluation of the compositional variations with respect to geographical origin.     

Effect of cottonseed oilcake inclusion on ostrich growth performance and meat chemical composition

This study investigated the effect of replacing dietary soybean oilcake meal with increasing levels of cottonseed oilcake meal (CSOCM) on the growth performance and meat (Iliofibularis muscle) chemical composition of ostriches in order to decrease total feed costs. A total of 105 ostriches were divided into five feeding groups according to the CSOCM inclusion level in the whole diet: Control (0% CSOCM), 3%, 6%, 9% and 12% CSOCM (of the whole diet), and fed with experimental diets from 6 to 13 months of age. As a result of feeding CSOCM, the final live weight and the average daily gain significantly increased in the 12% CSOCM group. The proximate composition, cholesterol content, mineral and fatty acid profile of the meat remained unaffected. Thus CSOCM may be used as an alternative protein source to the more expensive soybean oilcake meal in ostrich nutrition.     

Combination effects of ultra-high pressure and temperature on the physical and thermal properties of ostrich meat sausage (yor)

Ostrich meat sausages (yor) were subjected to ultra-high pressures of 300, 500 and 700 MPa for 40 and 60 min at 40 and 60 °C. Subsequently the physical properties of the products, colour, released and expressible water, gel strength and stress relaxation as well as their thermal characteristics (by differential scanning calorimeter, DSC) were determined. The effects of pressure, temperature and holding time significantly influenced the L^∗, a^∗ and b^∗ values. The amount of released plus expressible water significantly decreased with increasing pressure, temperature and holding time. The gel strength and equilibrium stress increased with increasing severity of treatment. DSC thermograms indicated that pressures of 700 MPa yielded gel networks involving completely denatured protein with the ability to retain water.     

Extending the shelf-life and proximate composition stability of ready to eat foods in vacuum or modified atmosphere packaging

The stability of the proximate composition (moisture, proteins, lipids and ash) and the microbiological state of cooked ‘ready to eat’ foods in vacuum or modified atmosphere packaging were examined and compared with conventionally packaged (in air) foods. The study was carried out for 7 and 29 days, during which time the food products were stored at 3°C. Vacuum or modified atmosphere packaging were effective for prolonging the shelf-life of the studied products up to 29 days with minimal changes in the proximate composition. Aerobic mesophilic, psychrotrophic microrganisms, and yeasts and moulds increased with time regardless of packaging type but more rapidly under conventional packaging.     

Applying an intelligent model and sensitivity analysis to inspect mass transfer kinetics,shrinkage and crust color changes of deep-fat fried ostrich meat cubes

The objectives of this study were to use image analysis and artificial neural network (ANN) to predict mass transfer kinetics as well as color changes and shrinkage of deep-fat fried ostrich meat cubes. Two generalized feedforward networks were separately developed by using the operation conditions as inputs. Results based on the highest numerical quantities of the correlation coefficients between the experimental versus predicted values, showed proper fitting. Sensitivity analysis results of selected ANNs showed that among the input variables, frying temperature was the most sensitive to moisture content (MC) and fat content (FC) compared to other variables. Sensitivity analysis results of selected ANNs showed that MC and FC were the most sensitive to frying temperature compared to other input variables. Similarly, for the second ANN architecture, microwave power density was the most impressive variable having the maximum influence on both shrinkage percentage and color changes.     

Purification and partial characterization of ostrich skeletal muscle cathepsin D and its activity during meat maturation

Cathepsin D was purified from ostrich (Struthio camelus) skeletal muscle using pepstatin-A chromatography. The enzyme was comprised of two subunits (29.1 and 14 kDa). The N-terminal amino acid sequence of both subunits were determined and showed high amino acid sequence identity to other cathepsin D homologs. Ostrich cathepsin D was optimally active at pH 4 and at a temperature of 45°C, and was strongly inhibited by pepstatin-A (K(i)=3.07×10(-9)M) and dithiothreitol. Cathepsin D activities from five ostriches were monitored over a 30-day period. Cathepsin D remained substantially active throughout the 30-day storage period with an average remaining activity of 112±8.57% at day 30 (mean value from 5 ostriches).     

鸵鸟油理化性质及脂肪酸组成分析

采用索氏提取法提取了在陕西养殖的鸵鸟油,室温分离得到液体油和固体脂.采用化学方法和气相色谱仪测定了两者常规理化指标和脂肪酸组成.结果表明,鸵鸟液体油和固体脂除碘值外其他理化指标稍有不同,其中脂肪酸组成及含量也有差异.液体油主要含有棕榈酸、油酸和亚油酸等,不饱和脂肪酸含量为63.96%,其中油酸含量最高,达到42.23%;固体脂主要含有棕榈酸、硬脂酸和油酸等,饱和脂肪酸含量为55.93%,其中棕榈酸含量最高,为45.23%.     

Physicochemical and sensory properties of healthier frankfurters as affected by walnut and fat content

This study evaluates the physicochemical and sensory properties of healthier frankfurters with 25% added walnut (WF) versus low-fat frankfurters (6% pork fat) (LF) and traditional frankfurters (18% pork fat) (NF). Results reveal that cooking losses were unaffected (p ? 0.05) by the formulation of frankfurters. The addition of walnut led to higher (p < 0.05) redness and yellowness values, while colour parameters did not differ significantly between LF and NF sausages. Frankfurters with added walnut (WF) presented higher (p < 0.05) hardness and chewiness values than LF and NF frankfurters. Differences in composition were also accompanied by changes in the microstructure of the gel/emulsions. Frankfurters with added walnut presented a flavour significantly different from meat and scored lower (p < 0.05) on texture preferences. However, all frankfurters scored the same for overall acceptability.     

Meat quality of kudu (Tragelaphus strepsiceros) and impala (Aepyceros melampus): Carcass yield, physical quality and chemical composition of kudu and impala Longissimus dorsi muscle as affected by gender and age

The meat quality of kudu and impala was compared. Live weight and carcass weight differed between species, genders and age groups. Impala had the highest dressing percentage while kudu had the highest live weight and carcass weight. Kudu had the lowest fat content while female animals had a higher fat and myoglobin content than males. Sub-adults had a higher ash content than adults. Species, gender and age had no effect of pH, drip loss, cooking loss or tenderness although kudu had higher L*, a*, b* and chroma values than impala. Impala sub-adults had significantly higher insoluble collagen, soluble collagen, total collagen and hydroxyproline content than kudu sub-adults. Kudu had the highest potassium levels while impala had the highest phosphorus levels. Potassium, sodium, iron and copper levels also differed between species.     

不同日龄和性别白羽王鸽肉品质、主要营养成分及肌纤维特性的比较研究

目的比较研究不同日龄和性别白羽王鸽胸肌肉的常规肉品质、主要营养成分和肌纤维特性。方法随机选取健康28日龄乳鸽、600日龄左右老鸽公(♂)母(♀)各30只,屠宰取胸肌待测。使用色差仪、pH计、膨胀仪、肌肉嫩度仪等测定常规肉品质指标,参照国标方法测定营养成分,制作石蜡切片并通过生物显微镜观察肌纤维特性。结果乳鸽胸肌肉肉色a值和b值均极显著高于老鸽(P0.01);乳鸽胸肌肉pH高于老鸽,且乳鸽(♂)显著高于老鸽(♂)(P0.05);不同日龄和性别对白羽王鸽胸肌肉失水率没有显著影响(P0.05);老鸽胸肌肉剪切力大于乳鸽,且老鸽(♂)显著大于乳鸽(♀)(P0.05)。不同日龄和性别白羽王鸽胸肌肉水分含量无显著差异(P0.05),蛋白质和脂肪含量有显著差异(P0.05);蛋白质和脂肪含量:老鸽(♀)老鸽(♂)乳鸽(♀)乳鸽(♂)。乳鸽胸肌肉肌纤维饱满致密,老鸽细且纤维之间的空隙较大。老鸽胸肌肉的肌纤维密度极显著高于乳鸽(P0.01),肌纤维直径极显著低于乳鸽(P0.01);相同日龄公母鸽胸肌肉肌纤维密度和肌纤维直径没有显著差异(P0.05)。结论性别仅对白羽王鸽胸肌肉中蛋白质和脂肪的沉积有影响,对常规肉品质和肌纤维特性影响不大。日龄对白羽王鸽胸肌肉的肉品质、微观结构和化学成分均有影响。乳鸽肉色红润,肉质鲜嫩,肌纤维饱满,脂肪含量低;老鸽肌纤维细密,肌间脂肪和蛋白含量高。     

Effects of modified atmosphere packaging (MAP) on the microbiological quality and shelf life of ostrich meat

Effects of various concentrations of O₂/CO₂ in modified atmosphere packaging on the microbiological quality and shelf-life of ostrich meat was investigated. Nine–12 months old ostriches were used. The iliofibularis muscle was cut into small cubes that were divided into five groups and then separately packaged under various gas mixes: air and O₂:CO₂:N₂ ratios of 80:20:0, 60:20:20, 60:40:0, and 40:40:20, using 2 different headspace ratios (1:1 and 3:1). The packaged meats were kept at 4 °C for 10 days and were analysed microbiologically, physico-chemically and sensorially. As a result, the meat quality and shelf-life of ostrich meat under various gas compositions were improved; microbial growth was delayed due to high CO₂ usage and shelf-life was increased by 5–7 days. However, an undesired loss of red colour of the ostrich meat may affect consumer acceptance.     

Proximate composition and mineral contents of the blue crab (Callinectes sapidus) breast meat, claw meat and hepatopancreas

The objective of this study was to determine the nutritional composition of the breast, claw meat and hepatopancreas of the blue crab (Callinectes sapidus). Samples were subjected to proximate (protein, fat, ash and moisture) and calcium, magnesium, phosphorus, potassium and sodium (Ca, Mg, P, K and Na) analyses. Protein, fat, ash and moisture of the breast, claw meat and hepatopancreas of the blue crab averaged 19.05, 0.59, 2.10 and 76.85 g/100 g, respectively. The results have revealed that this species is a rich source of protein, Ca, Mg, P and Na. Claw meat had higher protein concentrations (19.55 g/100 g) than both breast meat and hepatopancreas (18.81 g/100 g). Na was predominant element among minerals analysed. There were significant differences between Ca, Mg, P, K and Na contents of claw, breast meat and hepatopancreas of the blue crab. Information on the nutrient composition is needed to facilitate the processing, utilisation and marketing of blue crab products. Blue crab could balance human nutrition and could be used as an alternative dietary supplement of proteins and mineral matter.