Analytical Method for Differentiation of Chilled and Frozen-Thawed Chicken Meat
Abstract : Chilled and frozen chicken breast and thigh meat were stored at +4±1 oC and - 20±1 oC, respectively. Maillard reaction between ribose and meat proteins of the chicken samples was initiated. The changes in the ribose-induced Maillard reaction rate during chilled and frozen storage of chicken meat were evaluated on the bases of corrected absorbance values (A420*) and bovine melanoidin equivalent values (mg BME/g). Application of BME as a measure of ribose-induced Maillard reaction rate enables comparability of the data obtained by different spectrophotometers. It was found that the BME values of chicken meat frozen stored for more than 15 days were significantly (P<0.05) lower than BME values of chilled-stored samples. According to the suggested threshold limit values the chicken thigh and breast meat with BME values lower than 30 mg BME/g and 51 mg BME/g, respectively could be classified as frozen-thawed.
Freezing Effects on Food Quality
Fundamentals of food freezing: fundamental aspects of the freezing process. Muscle food products: red meats poultry and poultry products fish and seafoods cured and processed meats. Fruits and vegetables: fruits vegetables. Dairy and egg products: freezing of dairy products effects of freezing, frozen storage and thawing on eggs and egg products. Cereals and baked products: effects of freezing, frozen storage and thawing on dough and baked goods.
Hypoxanthine-based enzymatic sensor for determination of pork meat freshness
Abstract An enzyme sensor employing xanthine oxidase (XO), soluble or immobilised, in combination of an oxygen electrode has been developed and optimised to determinate the hypoxanthine (Hx) content in pork meat at different post-mortem times as measure of meat freshness. The amperometric signal obtained due to the oxygen depletion during the Hx oxidation was related with the consumed oxygen at 190 s in the soluble enzyme sensor or enzymatic rate at 10 s in the immobilised enzyme sensor. In both cases a linear relationship between the signal and the Hx concentration in the range 8.68–26.05 μM (R2 = 0.999) and 15.63–127 μM. (R2 = 0.995), respectively, was found. Both enzyme sensors exhibited very good working conditions and storage stability. A study of Hx oxidation was carried out in order to compare the Hx content measured by both sensors and those measured by high performance liquid chromatography (HPLC) obtaining a good agreement between both techniques. Therefore, the easy preparation and operation of both enzyme sensors suggests a reliable, rapid and an economical alternative for simple or multiple Hx measurements constituting a useful tool as quality control of meat freshness.