Abstract: For pork meat was one of the highly corruptibleproducts during logistics, the fast detection of total volatile basic nitrogen (TVBN)based on chromatic aberration method was researched and applied to observe thequality changes of warm fresh pork during logistics in winter and summer, as wellas the quality changes of chilled pork and vacuum-package chilled pork duringshort-time and long-time logistics. The results showthat the logistics quality of warm pork changes quickly, and the logistics quality of chilling pork changes slowly, whilethe logistics quality of chilling pork with vacuum packagehas least change. Low temperature logisticsof fresh pork is recommended, and the quality would be best kept in thechilling pork logistics with vacuum package.
Key Words:fresh pork,logistics,TVBN,chromatic aberration
1. INTRODUCTION
Slaughter,storage, transportation, distribution and sale are composed of fresh porklogistics during which the factor of temperature plays an important role to thequality of pork. Akamittath et al.(1990) found an increase in Thiobarbituric acid reactive substances (TBARS) concomitantwith a decrease in product redness, measured as the tristimulus parameter a*, forrestructured pork during frozen storage at -10℃for upto 8 weeks. Jensen et al.(1998)found increased lipid oxidation during chill storage of meat from a standardfeeding regime compared to meat from pigs with high levels of a-tocopherol.Ultimate pH has previously been shown to be crucial for the quality of freshpork chops during chill storage under retail conditions. (Juncher et al.,2001). The bacterial diversityand main flora of chilled meat under different storage conditions have beenextensively studied according to traditional cultivation methods (Blixt andBorch, 2002; Borch et al., 1996;Gill, 1996; Jay et al., 2003). Thebacterial composition and its change were complex, and the bacterial diversityreduced in chilled pork during storage whether by tray- or vacuum-packaging. (Daintyand Mackey, 1992; Olsson et al.,2003). The previous researches are mostly concentrated on the quality changesabout fresh pork during storage, but the transportation and sale are alsocritical to keep pork fresh in the pork supply chain. Based on total volatilebasic nitrogen (TVBN), one of the evaluation indexes to quality of fresh meat(Gómez-Estacaet al.,2007),the TVBN changes of fresh pork during transportation, storage and sale, in thispaper, would be detected to expose the quality changes rules during logisticsabout fresh pork in contrast to vacuum-packaged pork.
2. MATERIALS AND METHODS
2.1 Sampling
Pork hindquarter steaks (weight: 100-250g) were removed from pork carcasses in acommercial slaughterhouse. Of all the pork steaks, some were vacuum-packagedand the others were naked. At 28℃external environment, theoscillating incubator with constant temperature and 2 Hz oscillatory frequency wasused to simulate the refrigerated transportation, and the incubator was alsoused to simulate the storage and sale when the oscillator was shut off.