Application of Vis–NIR hyperspectral imaging in classification between fresh and frozen-thawed pork Longissimus Dorsi muscles

Fresh and frozen-thawed (F-T) pork meats were classified by Vis–NIR hyperspectral imaging. Eight optimal wavelengths (624, 673, 460, 588, 583, 448, 552 and 609 nm) were selected by successive projections algorithm (SPA). The first three principal components (PCs) obtained by principal component analysis (PCA) accounted for over 99.98% of variance. Gray-level-gradient co-occurrence matrix (GLGCM) was applied to extract 45 textural features from the PC images. The correct classification rate (CCR) was employed to evaluate the performance of the partial least squares-discriminate analysis (PLS-DA) models, by using (A) the reflected spectra at full wavelengths and (B) those at the optimal wavelengths, (C) the extracted textures based on the PC images, and (D) the fused variables combining spectra at the optimal wavelengths and textures. The results showed that the best CCR of 97.73% was achieved by applying (D), confirming the high potential of textures for fresh and F-T meat discrimination.     

锅包肉的烹饪工艺及其影响因素研究

通过感官评价研究锅包肉烹饪工艺条件对其感官品质的影响,同时利用正交试验对糖醋汁配比工艺参数进行优化研究。结果表明:选择里脊肉作为锅包肉原材料最优,锅包肉选用玉米淀粉挂糊最佳,锅包肉糖醋汁最优配比为番茄沙司含量为20%、蔗糖含量为35%、白醋含量为45%、食盐含量为1%。     

Deep freezing to maintain the freshness of pork loin during long-term storage

Food Science and Biotechnology - As storage temperature impacts frozen meat quality, we evaluated the ideal freezing and storage temperatures for pork loin, and effects of long-term storage...     

Prevalence of Yersinia enterocolitica from food and pigs in selected states of Malaysia

The aim of this study was to determine the prevalence of Yersinia enterocolitica and its bioserotypes from food and pigs in Malaysia. Fifty-eight raw porcine (raw pork meat, internal organs and other parts) and 48 non-porcine food (raw beef, poultry products, seafood, vegetables, tofu, and pasteurised milk) from wet markets located in Kuala Lumpur, Selangor, Perak, and Pahang were examined for the presence of Y. enterocolitica. Specimens (nasal, oral and rectal swabs) from 165 pigs (from nine farms) located at central and northern parts of Malaysia were also collected for Y. enterocolitica detection. Presumptive isolates were characterised biochemically and further confirmed by PCR. Out of 58 raw porcine food, Y. enterocolitica was detected in 7 (12.1%) samples in which raw pork meat (whole meat) had the highest prevalence 5/21 (23.8%), followed by raw pork liver 1/5 (20.0%) and raw pork intestine 1/8 (12.5%). No Y. enterocolitica was isolated from the 48 non-porcine foods. Overall, two pathogenic (bioserotypes 3 variant/O:3 and 1B/O:8) and one non-pathogenic (bioserotype 1A/O:5) Y. enterocolitica strains were isolated from food. Out of 165 pigs examined, 3 (1.8%) pigs were carriers for Y. enterocolitica. All 3 pigs were asymptomatic grower pigs from Penang, carried Y. enterocolitica bioserotype 3 variant/O:3. Post-enrichment PCR approach gave a higher prevalence, 60.3%, 41.7% and 27.9% for porcine food, non-porcine food and pigs, respectively. Both pathogenic and non-pathogenic Y. enterocolitica were present in our domestic pigs and food. Improper food handling and processing may cause cross contamination of this pathogen to humans, affirms a potential risk for public health.     

Preparation of ractopamine-tetraphenylborate complexed nanoparticles used as sensors to rapidly determine ractopamine residues in pork

In this work, we reported a simple, fast, and sensitive determination of ractopamine (RAC) residues in pork by using novel ractopamine-tetraphenylborate complexed nanoparticles (RT NPs) as sensors. The prepared RT NPs exhibited a fast response time of 10 s, a wide linear range from 0.1 to 1.0 × 10⁻⁷ mol/L, and a very low detection limit of 7.4 × 10⁻⁸ mol/L. The prepared sensor also presents a high selectivity for ractopamine under different pH conditions ranged from 2.85 to 7.18. These results reveal that the fabricated RT NPs can be used as efficient electrochemical sensors to determine ractopamine in animal productions.     

Texture,sensory and swallowing characteristics of high-pressure-heat-treated pork meat gel as a dysphagia diet

To develop a soft meat product for a dysphagia diet, high-pressure technology was applied. Pressure-heat-treated ground pork meat (PH) was prepared from ground pork mixed with water (ground meat: water, 1:0.5 or 1:1) and salt (1.5%). PH-gels were made from these meat homogenates by treatment at 400 MPa for 20 min, followed by heat treatment. Heat-treated pork meat homogenates (H) were also prepared. The hardness and adhesiveness of the 1:1PH-gel was lower than those of the 1:1H-gel. The PH-gel scored higher in sensory evaluations of elasticity, smoothness and ease of swallowing. Scanning electron micrographs indicated that the superior textural property of the 1:1PH-gel was caused by a network of myosin filaments. Videofluoroscopic examination of swallowing revealed that the 1:1PH-gel was easy to swallow and left little residue in the oropharynx. These results proved the utility of pressurization in creating a dysphagia meat diet.     

GC-MS analysis of off-odor volatiles from irradiated pork

The main compounds of off-odor volatiles from irradiated refrigerated vacuum-packaged pork were analyzed by gas chromatograph/mass spectrometer （GC-MS）. The analytical results showed that the main compounds of off-odor volatiles were dimethyl disulfide, dirnethyl sulfide, dimethyl trisulfide, S-methyl thioacetate, and methanethiol. It was proved that the off-odor volatile came from irradiated S-containing amino acid and thiamin.     

Meat quality and cooking attributes of thawed pork with different low field NMR T(21)

A relationship of low field NMR T(2) components to meat quality and cooking attributes of pork was investigated. Longissimus muscle was removed from 23 pig carcasses at 24h postmortem for meat quality measurements and cooking test. Frozen samples were classified into three groups by LF-NMR T(21) of thawed samples: A (<40ms), B (40-44ms) and C (>44ms). There were significant differences (P<0.05) in pH, lightness (L* value) and pressing loss among the three groups. Cooking time to attain 70°C was slightly lower in group C than the other groups. Shear force value of cooked samples was not affected by T(21). The component T(21) correlated (P<0.05) with L* value, muscle pH and pressing loss, while L* value correlated (P<0.05) with thawing loss and muscle pH. Therefore, combined LF-NMR and color measurements could be a good way to differentiate water holding capacity of pork.     

猪肉矿物质元素的测量

试验旨在增强人们对猪肉矿物质元素营养价值的认识,为人们日常膳食的搭配提供依据。分别在河南省五个不同市、县随机选取90Kg左右生猪各10头,按照瘦肉型种猪性能测定技术规程进行屠宰。取背最长肌进行矿物质元素含量测量。结果表明:猪肉中钾和钠含量较高,3657.70mg/Kg、387.35mg/Kg;锌和铁的含量丰富,6.25mg/Kg、8.50mg/Kg;钙和锰含量较少,28.81mg/Kg、0.0651mg/Kg;铜和镉的含量在国家的允许范围之内,2.26mg/Kg、0.0909mg/Kg。猪肉不能完全满足人们对所有矿物质元素的需要。