Anang D M, Rusul G, Radu Son, Bakar Jamilah, Beuchat L R
Department of Food Science, Faculty of Food Science and Technology, University of Putra Malaysia, 43400 UPM, Serdang, Selangor D.E., Malaysia.
J Food Prot. 2006 Aug;69(8):1913-9. doi: 10.4315/0362-028x-69.8.1913.
Oxalic acid was evaluated as a treatment for reducing populations of naturally occurring microorganisms on raw chicken. Raw chicken breasts were dipped in solutions of oxalic acid (0, 0.5, 1.0, 1.5, and 2.0%, wt/vol) for 10, 20, and 30 min, individually packed in oxygen-permeable polyethylene bags, and stored at 4 degrees C. Total plate counts of aerobic bacteria and populations of Pseudomonas spp. and Enterobacteriaceae on breasts were determined before treatment and after storage for 1, 3, 7, 10, and 14 days. The pH and Hunter L, a, and b values of the breast surface were measured. Total plate counts were ca. 1.5 and 4.0 log CFU/g higher on untreated chicken breasts after storage for 7 and 14 days, respectively, than on breasts treated with 0.5% oxalic acid, regardless of dip time. Differences in counts on chicken breasts treated with water and 1.0 to 2.0% of oxalic acid were greater. Populations of Pseudomonas spp. on chicken breasts treated with 0.5 to 2.0% oxalic acid and stored at 4 degrees C for 1 day were less than 2 log CFU/g (detection limit), compared with 5.14 log CFU/g on untreated breasts. Pseudomonas grew on chicken breasts treated with 0.5% oxalic acid to reach counts not exceeding 3.88 log CFU/g after storage for 14 days. Counts on untreated chicken exceeded 8.83 log CFU/g at 14 days. Treatment with oxalic acid caused similar reductions in Enterobacteriaceae counts. Kocuria rhizophila was the predominant bacterium isolated from treated chicken. Other common bacteria included Escherichia coli and Empedobacter brevis. Treatment with oxalic acid caused a slight darkening in color (decreased Hunter L value), retention of redness (increased Hunter a value), and increase in yellowness (increased Hunter b value). Oxalic acid has potential for use as a sanitizer to reduce populations of spoilage microorganisms naturally occurring on raw chicken, thereby extending chicken shelf life.
研究了草酸作为一种处理方法，用于减少生鸡肉上自然存在的微生物数量。将生鸡胸肉浸入草酸溶液（0、0.5、1.0、1.5和2.0%，重量/体积）中10、20和30分钟，分别装入透气的聚乙烯袋中，并在4℃下储存。在处理前以及储存1、3、7、10和14天后，测定鸡胸肉上需氧菌的总平板计数以及假单胞菌属和肠杆菌科的数量。测量鸡胸肉表面的pH值以及亨特L、a和b值。无论浸泡时间如何，储存7天和14天后，未处理的鸡胸肉上的总平板计数分别比用0.5%草酸处理的鸡胸肉高约1.5和4.0 log CFU/g。用水处理和用1.0至2.0%草酸处理的鸡胸肉上的计数差异更大。用0.5至2.0%草酸处理并在4℃下储存1天的鸡胸肉上的假单胞菌属数量低于2 log CFU/g（检测限），而未处理的鸡胸肉上为5.14 log CFU/g。用0.5%草酸处理的鸡胸肉在储存14天后，假单胞菌生长至计数不超过3.88 log CFU/g。未处理的鸡胸肉在14天时计数超过8.83 log CFU/g。草酸处理使肠杆菌科的计数有类似程度的减少。嗜根考克氏菌是从处理过的鸡肉中分离出的主要细菌。其他常见细菌包括大肠杆菌和短稳杆菌。草酸处理导致颜色略有变深（亨特L值降低）、红色保留（亨特a值增加）以及黄色增加（亨特b值增加）。草酸有潜力用作消毒剂，以减少生鸡肉上自然存在的腐败微生物数量，从而延长鸡肉的保质期。
