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.
Ribose-Induced Maillard Reaction as a Quality Index in Frozen Minced Chicken and Pork Meats
Minced meats underwent denaturation, oxidation and aggregation during frozen storage, causing decrease in denaturation enthalpy, sulfhydryl contents and protein solubility, as well as increase in protein carbonyl and disulfide contents. These changes were more evident in samples stored at −4C than those stored at −20C, as reactions occurred at faster rates at higher temperature. The addition of ribose on thawed minced meats followed by heating at 95C initiated Maillard reaction browning. Browning index () was significantly higher (P < 0.05) in fresh minced meats than in frozen ones, decreased with storage time and were lower in minced meat stored at −4C than those stored at −20C. The biochemical changes in meat proteins during frozen storage reduced the availability of basic amino acids to take part in the Maillard reaction. Hence, could be used as freshness index in minced chicken and minced pork. 
 
 
 
Practical Applications 
 
Long-term frozen storage of meat causes degradative changes which leads to the loss of functionality, flavor, texture and organoleptic properties of the meat. Due to these losses, fresh meat is often perceived to be of a better quality and often valued at a higher market price compared to those of frozen meat. This study proposed an alternative, simpler, quicker and cheaper method to identify between fresh versus frozen/thawed meat. The proposed method was based on the Maillard reaction between proteins of meat and ribose, yielding brown pigments (melanoidins) that can be measured as absorbance and converted into a freshness index. It was demonstrated that the biochemical degradation during frozen storage reduces the availability of meat proteins to react with ribose, yielding lower freshness index as compared to those of fresh meat. Thus, freshness index could be used as a quality control method to ascertain meat freshness and to evaluate supplier's reliability.
Mite population density analysis of stored dried apricots in Turkey
The aim of this study was to determine the population density of mite species attacking stored dried apricots in Malatya, Elazig and Izmir regions of Turkey. Storage construction types and duration of storage were also considered. The samples were collected during 2000–2003 in the most important apricot producing areas (Malatya and Elazig) and the exporting center (Izmir). Frequency of occurrence and rates of intensity of infestations were determined (16.50% from Malatya, 3.19% from Elazig and 80.49% from Izmir). A total of 16 mite species belonging to 13 genera and 11 families were identified during the surveys. The pest species Carpoglyphus lactis (L.) (Astigmata: Carpoglyphidae) was the most abundant species recorded (69.14% of samples). The highest infestation value recorded was 15,534 mites per kg.