改进的规范割方法提取肉品图像中肌肉和脂肪

肉品图像中脂肪与肌肉的精确提取是无损检测的关键技术之一,针对这一问题,在规范割方法（Normalized cut,Ncut）的基础上,为了减少计算复杂度,提出了一种改进算法。首先,利用基于矩的阈值选择方法将肉品区域从背景中分割出来;其次,量化色彩等级,为肉品区域创建彩色直方图;最后,计算彩色直方图的相似度矩阵,并使用规范割做为谱聚类测度对直方图进行划分,按照直方图划分结果提取肌肉和脂肪。实验表明,和基于像素的谱聚类算法相比,改进算法不但降低了计算复杂度,且能有效提取肌肉与脂肪。     

Combined effect of chitosan and modified atmosphere packaging for shelf life extension of chicken breast fillets

The combined effect of dipping in a chitosan solution (1 g/100 ml) and packaging under modified atmosphere (MAP, 70% CO₂, 30% N₂) on shelf life extension of refrigerated chicken fillets was investigated. Microbiological (Total Viable Counts, Pseudomonas spp., Lactic Acid Bacteria and Enterobacteriaceae), physicochemical (headspace gas composition, pH, color and Thiobarbituric Acid test) and sensory (odor and taste) parameters were monitored for up to 14 days. TVC were 3.9–4.9 log cfu/g lower on day 6 of storage in treated vs. untreated air-packaged samples with the strongest effect being shown by the combination of chitosan plus MAP. A similar reduction in LAB, Pseudomonads and Enterobacteriaceae was recorded during storage. pH values varied between 5.73 (day 8, for acetic acid treated samples) and 6.28 (day 6, for air-packaged samples). Malondialdehyde (MDA) values ranged between 0.19 and 0.80 mg/kg indicating negligible oxidation of lipids. The color parameter L* decreased with time in the air-packaged samples but remained unaffected in all other treatments. Parameters a* and b* were not significantly affected by the chitosan or the MAP treatments. Based on the microbiological and sensory data, shelf life of air-packaged, chitosan-treated, MAP-treated and chitosan/MAP treated samples was 5, 11, 12 and 14 days, respectively.     

Quantitation of Lamb Content in Mixtures with Raw Minced Beef Using Visible, Near and Mid-Infrared Spectroscopy

Samples of beef (32), lamb (33) and 5%, 10% and 20% (w/w) lamb-in-beef mixtures (33 each) were minced and reflectance scanned in the visible, near and mid-infrared spectral regions. Partial least squares (PLS) regression models were developed to predict percentage lamb content using each spectral region alone and combinations of all three. The most accurate models combined mid-IR (800-2000 cm^-1) and near IR (1100-2498 nm) spectral data following 2^nd derivatization; standard errors of prediction of 0.91% (0–20% range in lamb content) and 4.1% (0–100% range in lamb) were obtained. This technique may be useful for screening such meat mixtures.     

Effect of high pressure treatments combined with various levels of κ-carrageenan on cold-set binding in restructured pork

This study investigated the effects of high pressure processing and κ-carrageenan on cold-set binding in restructured pork meat. High pressure (>200 MPa) combined with carrageenan level higher than 1.5% caused increased breaking force and tensile strength ( P  < 0.05). Increasing the pressure level caused a continuous κ-carrageenan network in the junctions between meat particles, as confirmed by scanning electron microscopy imaging. With regard to the water binding properties, all treatments showed moisture content ranging between 74% and 76%. Increases in pressure levels and holding times tended to improve the water-holding capacity (WHC) of restructured pork; however, the κ-carrageenan concentration showed no relation with WHC. Cooking loss decreased significantly ( P  < 0.05) with increases in both pressure level and κ-carrageenan concentration. By increasing pressure levels, both the L ^*- and a ^*-values increased, but the b ^*-value showed no significant difference ( P  > 0.05) among the treatments, with the exception of 100 MPa for 30 min. The addition of κ-carrageenan had no effect on colour ( P  > 0.05). Therefore, the results indicate that pressure above 200 MPa and addition of 1.5% carrageenan has potential use in cold-set meat restructuring.     

天然防腐剂——那他霉素

The article mainly introduced the character of antimicrobial Natamycin, the preservative mechanism, the application in meat products was reviewed and the development of Natamycin was proposed.     

功能型肉制品的研究进展

本文从功能型肉制品开发方向、种类以及开发途径等方面对功能型肉制品近几年来的研究进展进行了综述。     

Use of dairy proteins in lean poultry meat batters – a comparative study

The use of dry whole milk, skimmed milk, caseinate, regular and modified whey, at 2% level (w/w) and with 2% additional protein level was studied in a chicken breast meat system with 51% water addition. At the 2% (w/w) level, all dairy proteins significantly reduced cooking loss compared with the control, with caseinate showing the best results. When compared on an equal protein level (2% total protein), the best performing ingredients were the whole milk and modified whey. A similar observation was made in their effect on the products’ hardness and fracturability. A cost analysis revealed that modified whey provided the most economical ingredient even when used in quantities three times greater than that of as caseinate. Microscopy results showed the formation of larger fine‐protein‐matrix regions in the treatments that provided higher fracturability 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.