Sibomana M S, Ziena L W, Schmidt S, Workneh T S
Bioresources Engineering, School of Engineering, University of KwaZulu-Natal, Private Bag X0l, Pietermaritzburg, Scottsville 3209, South Africa.
Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X0l, Pietermaritzburg, Scottsville 3209, South Africa.
J Food Prot. 2017 Feb;80(2):345-354. doi: 10.4315/0362-028X.JFP-16-229.
Postharvest microbial spoilage due to suboptimal transportation and packaging conditions is a key concern for the South African tomato industry. This study investigated the influence of washing with tap water or aqueous disinfectant solutions (chlorinated and anolyte water) on the microbiological quality of tomatoes during storage after transportation in nonrefrigerated trucks along two supply routes when packaged in crates and boxes. Route 1 was 1,093 km from field to storage site, while route 2 was 1,057 km. During transport, the temperature in the trucks fluctuated between 16 and 28°C and the relative humidity between 25 and 94% for route 1, while for route 2, the temperature was between 16 and 30°C and the relative humidity between 28 and 71%. Tomatoes at the pink maturity stage were sampled, treated, and stored for 28 days (11°C). The tomato firmness before treatment was 24.8 N (box samples) and 17.4 N (crate samples) for route 1, whereas it was 22.1 N (box samples) and 20.2 N (crate samples) for route 2. Temperature fluctuation during transportation led to water condensation on tomato surfaces. Tomatoes treated with anolyte water showed the lowest microbial surface burden during storage, with mean aerobic plate counts (APC) of 2.9 log CFU/cm, coliform counts (CC) of 1.1 log CFU/cm, and fungal counts (FC) of 2.3 log CFU/cm. Overall, of the total APC recorded during storage, anolyte-treated samples contributed 9% while chlorinated water-treated samples contributed 30%. Of the total CC, anolyte samples presented 3% while chlorinated water samples made up 12%, and of the total recorded FC, anolyte samples contributed 7% while chlorinated water samples made up 22%. Scanning electron microscopy imaging showed surface cracks, which enable microbial colonization in crate-transported tomatoes. A combination of anolyte treatment and box packaging during transport resulted in the best microbiological quality during storage. The findings of this investigation provide motivation for the adoption of anolyte water as a postharvest disinfection treatment in the tomato industry.
由于运输和包装条件欠佳导致的采后微生物腐败是南非番茄产业的一个关键问题。本研究调查了用自来水或含氯消毒剂溶液（含氯水和阳极液水）清洗对番茄在非冷藏卡车中沿两条供应路线运输后，以板条箱和盒子包装储存期间微生物质量的影响。路线1从田间到储存地点为1093公里，而路线2为1057公里。运输过程中，路线1的卡车温度在16至28°C之间波动，相对湿度在25至94%之间，而路线2的温度在16至30°C之间，相对湿度在28至71%之间。对处于粉红成熟阶段的番茄进行采样、处理，并在11°C下储存28天。路线1处理前番茄的硬度，箱装样品为24.8 N，板条箱装样品为17.4 N，而路线2箱装样品为22.1 N，板条箱装样品为20.2 N。运输过程中的温度波动导致番茄表面出现冷凝水。用阳极液水处理的番茄在储存期间显示出最低的微生物表面负荷，平均需氧平板计数（APC）为2.9 log CFU/cm，大肠菌群计数（CC）为1.1 log CFU/cm，真菌计数（FC）为2.3 log CFU/cm。总体而言，在储存期间记录的总APC中，阳极液处理的样品占9%，而含氯水处理的样品占30%。在总CC中，阳极液样品占3%，而含氯水样品占12%，在记录的总FC中，阳极液样品占7%，而含氯水样品占22%。扫描电子显微镜成像显示有表面裂缝，这使得微生物能够在板条箱运输的番茄中定殖。运输过程中阳极液处理和箱装的组合在储存期间产生了最佳的微生物质量。本调查结果为番茄产业采用阳极液水作为采后消毒处理提供了动力。
