超声波处理对淘汰蛋鸡嫩化效果的初步研究

采用超声波对淘汰蛋鸡肉的嫩化效果进行了初步的研究，对超声波的频率，功率，处理时间及处理媒质CaCl2的不同浓度进行了测试对比，结果表明：超声波与CaCl2相结合对淘汰蛋鸡肉的嫩化效果明显，超声渡的最佳频率为26．4kHz，功率为400W，处理时间15min，处理媒质CaCl2浓度为250mmol／L。     

QUALITY AND STORAGE STABILITY OF CHICKEN MEAT PATTIES INCORPORATED WITH LINSEED OIL

ABSTRACT

Low‐fat (<10% total fat) chicken meat patties (CMP) with different levels of linseed oil (LO) i.e., 0, 2, 3 and 4% (control, T₁, T₂ and T₃) were evaluated for their nutritive, processing, textural and storage qualities. The cooking yield, fat and moisture retention were comparable in control and LO‐treated products. The dimensional parameters were better maintained for T₂ among the LO treatments_. The sensory panelists rated T₂ as the best among treatments with comparable sensory attributes to control patties. The selected 3% level of LO was compared with the control for color, texture and fatty acid profile. The lightness (L*) and redness (a*) values were significantly (P < 0.05) less, whereas yellowness (b*) was significantly (P < 0.05) higher for the developed CMP than the control. The chewiness value was higher in control, whereas firmness and springiness were comparable in both the products. The total saturated fatty acid (SFA) content was significantly (P < 0.05) decreased, whereas α‐linolenic acid increased significantly (P < 0.05) in the developed CMP. The ratio of polyunsaturated fatty acids (PUFAs) and SFAs was increased, whereas n‐6/n‐3 decreased in developed CMP. CMP with 3% LO remained physicochemically and microbiologically stable with some deterioration in sensory attributes during aerobic refrigerated (4 ± 1C) storage of 25 days.

PRACTICAL APPLICATIONS

LO is a rich source of omega‐3 fatty acid and is used in the feed of the meat animals for nutritionally better quality meat, which requires long period of rearing and is costly. However, the direct incorporation of LO in the processed meat products poses various technological problems. Therefore, the efficacy of LO as a partial substitute of vegetable oil in the low‐fat omega‐3‐enriched meat products was assessed. The developed processing technology can be commercially exploited for the development of functional/health‐oriented meat products with low fat and low energy, rich in omega‐3 fatty acid, and balanced in PUFA and SFA ratio.

     

QUALITY OF NUGGETS PREPARED FROM FRESH AND SMOKED SPENT LAYER CHICKEN MEAT

Nuggets were prepared from fresh and smoked meats of spent layer chicken of age approximately 18 months, packed in polyethylene bags and stored at -18 ± 2C for 6 months. Thawed nuggets were fried on hot pan coated with refined sunflower oil and product quality was evaluated. Nuggets from smoked chicken had lower (P ± 0.05) moisture and higher fat contents and lower weight loss on frying compared to fresh meat nuggets. Free fatty acid (FFA expressed as percent of oleic acid) increased from 3.6 to 3.9 and 3.2 to 3.7, and thiobarbituric acid (TBA) values (mg malonaldehyde/kg sample) increased from 0.90 to 1.19 and 0.63 to 0.71 for fresh and smoked meat nuggets, respectively, during frozen storage for 6 months. Shrinkage in product diameter on frying ranged from 4.6 to 5.0%. Warner-Bratzler shear values ranged from 0.89 to 1.28 lbs for all products stored frozen up to 6 months. Sensory quality scores for smoked meat nuggets were significantly (P ± 0.05) higher, except for juiciness (P ≥ 0.05), than for fresh meat nuggets. Smoked chicken meat produced better nugget products compared to fresh meat as indicated by lower FFA and TBA values and better sensory quality attributes. Products packed in polyethylene bags can be stored at -18 ≥ 2C for up to 6 months without marked deterioration in product quality.     

COMMERCIAL TESTING AND OPTIMIZATION STUDIES OF THE SURFACE PASTEURIZATION PROCESS OF CHICKEN1

The performance of the surface pasteurization process to reduce the bacteria levels on the surface of chicken was tested on carcasses received from federally inspected commercial processing plants. These tests were made with carcasses that had been chilled and shipped overnight with ice packs. The tests and follow‐up experiments showed the visceral cavity was not treated as effectively as the outside. A second series of tests with chicken halves which eliminated the difficulty with the cavity, produced significant kills in E. coli, coliform, and total aerobic plate counts. Further research with chicken purchased at the supermarket established optimum process conditions as initial vacuum of 0.1 s, steam at 138C for 0.1 s, and final vacuum of 0.5 s. At these conditions, for half carcasses, bacteria kills for E. coli, coliforms, and APC generally ranged from approximately 0.5 to 1.0 log cfu/mL. The process is being modified to assure adequate treatment of the cavity     

SENSORY QUALITY OF CHICKEN MEAT AS A FUNCTION OF ITS FATNESS: COMPARISON OF MEAT LOAF WITH MEAT COOKED IN WATER1

Broiler chicken carcasses were classified as being lean, medium or fat, according to the proportion by weight of abdominal fat. The sensory quality was evaluated of breast and dark meat cooked separately in water, and of meat loaf containing both breast and dark meat. When cooked in water, the differences in the degree of fatness were found to have essentially no effect on the sensory quality. When cooked as meat loaf, the product of medium fatness was found to have the highest sensory quality, followed by the fat meat product and finally by the lean meat product.     

A NEW APPROACH TO CORRELATE TEXTURAL AND COOKING PARAMETERS WITH OPERATING CONDITIONS DURING DOUBLE-SIDED COOKING OF MEAT PATTIES

Cooking and textural parameters during double-sided cooking of hamburger patties were correlated with volume-averaged temperature at the end of the cooking process and gap thickness between plates. Frozen patties were cooked in a clamshell grill set at different plate surface temperatures (177C; 191C; 204C; 218C), for different gap thicknesses (9.65 mm; 10.55 mm; 10.55 mm; 11.05 mm) for 120 s. A decrease in the gap thickness and an increase in the plate surface temperature resulted in an increase in the cooking loss values (24–36%) and in a decrease of press juice values (8–25%). The values of peak load (183–215 N), modulus (16–19 N/mm), work needed in shearing (2300–2800 Nmm), hardness (25–32 N), cohesiveness (0.76–0.83), and chewiness (107–152 Nmm) of the patties increased when the gap thickness decreased and the plate surface temperature increased. There was no effect of the variables studied on springiness. The correlation equations involving the operating variables and quality parameters obtained are simple and useful in developing optimal process conditions.     

A STUDY OF HIGH PRESSURE WATER JETS FOR CUTTING CHICKEN BREAST MEAT

A replicated experiment was conducted to determine optimum settings for orifice size, operating pressure, and nozzle traverse speed for cutting boneless chicken breast meat with high-pressure water jets. Three orifices of 0.076, 0.127 and 0.178 mm were tested with different water pressures in the 90 to 224 MPa range and nozzle traverse speeds in the 50 to 800 mm/s range. A 0.127-mm orifice working with water pressure in the range of 179 to 224 MPa and at 100 mm/s or slower cutting speed gave best results in this study to produce sharp clean cuts. Water jets from a 0.178-mm orifice frequently caused too much meat loss especially at higher water pressures and slower nozzle speeds. Variations in chicken filet thickness also had significant effect on chicken breast meat cutting quality and depth with both 0.076 and 0.127-mm orifices.     

果蔬片微波干燥特性及最佳工艺研究

通过对利用微波干燥香蕉片的研究，揭示了微波干燥果蔬片的失水特性。同时，进行四因素三水平的正交实验以及二因素三指标的二次正交回归实验，得出各指标的回归方程，并进行参数优化，从而得到最佳工艺条件：前期发射功率为900W、前期时间2min、后期发射功率397W、后期时间11．3min。     

D- AND z-VALUES OF SALMONELLA IN GROUND CHICKEN BREAST MEAT

The heat resistance of a Salmonella composite of serotypes Typhimurium, Enteritidis, Montevideo, Mbandaka, Heidelberg and Thompson was evaluated in ground chicken breast meat using an end-point procedure in pouches. A 7D process for Salmonella in chicken was approximately 3 s at 160F (71.1C) with a z-value of 10.3F (5.7C). The data presented here may help cooked chicken products manufacturers design safe processes that meet the USDA Food Safety and Inspection Service performance standard.     

ATTACHMENT OF CERTAIN BACTERIAL STRAINS TO CHICKEN AND BEEF MEAT

The attachment of bacteria to chicken and beef meat with and without fascia was studied. It was found that bacteria attach readily to the meat surfaces. The kinetics of attachment depend on the bacterial strain, as well as on the meat surface. Of the bacteria tested, Pseudomonas EBT/2/143 attached most readily to all meat surfaces examined. Chicken breast with fascia was the best surface for attachment.
A study was also made of the effects of storage on the multiplication of the attached bacteria and the feasibility of removing them. A high level of Salmonella infantis was found in comparison to the other bacteria after 24 h of storage at 20°C.
More investigations are needed to find out whether other serotypes of salmonellae will multiply to similar levels on these surfaces.
After micro-colonies began to form, the newly generated bacteria were easy to remove. The hygienic consequence of this phenomenon is discussed.