Extending the Lifetime of Frying Oil through Optimization of Fryer Cleaning.

With increases in consumer demand for fried foods in Japan over the last several decades, the consumption of frying oil has also steadily increased. Fryers used in restaurants to cook large quantities of food are typically cleaned using neutral kitchen detergents at the end of the day after removing the oil from the tank. However, significant amounts of debris can remain in the fryer after cleaning, possibly accelerating oil deterioration and thus reducing the quality of the fried foods. In this study, debris obtained from fryer tanks used in actual restaurants was assessed using scanning electron microscopy-energy dispersive X-ray spectroscopy together with Fourier transform infrared spectroscopy, and were determined to comprise polymerized oil and carbonized organic matter. Experiments using artificially prepared debris confirmed that these materials increased the acid value (AV) of frying oil. Trials in two restaurants serving similar amounts of fried chicken, French fries and doughnuts examined the effects of cleaning the fryer with either an alkaline detergent or a neutral kitchen detergent on debris removal and oil life. The alkaline detergent was found to completely remove debris while the neutral detergent left significant amounts of debris. After cleaning, the fryers were operated with new oil as usual and the deterioration of this oil was monitored by assessing the color difference, AV, carbonyl value and peroxide value. These indices increased 1.3 to 2.0 times faster in the case that the neutral kitchen detergent was used, suggesting that cleaning fryer tanks with an alkaline detergent could contribute to extending the lifetime of frying oil, reducing food losses and thus achieving sustainable development goals.

Salmonella contamination and hazard analysis in a storage facility for feed materials in Japan.

AIMS: To reduce Salmonella contamination of animal feeds, Salmonella contamination in a feed materials storage facility was investigated, and hazard analysis was performed to acquire the basic information necessary to establish a control method for Salmonella. The result is that managers of feed materials storage facilities will be able to introduce the Hazard Analysis and Critical Control Point (HACCP) systems to quickly and efficiently. METHODS AND RESULTS: A total of 472 samples, including deposits, adhesions, environment samples and materials, were investigated. The detection rate in the storage facility was 5.1% (24/472) over the three-year investigation period. The serovars of detected Salmonella were Agona, Anatum, Bron (or Agbeni), Chester, Infantis, Mbandaka, Minnesota, Muenster, Sinstorf, Typhimurium, O18:- and O1,3,19:-. As a result of hazard analysis after confirming the multiplication factors and detection rate, important hazards were judged to be the outdoor equipment and dust collector. CONCLUSIONS: The risk of Salmonella contamination in storage facilities was clarified. Important Salmonella hazards in storage facilities are Salmonella-contaminated feed materials, multiplication factors such as rainwater and dew condensation, and Salmonella-accumulated dust in dust collectors for fine-powder recovery. These results suggest that proper control of these hazards could reduce the risk of Salmonella in storage facilities. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report describing actual Salmonella contamination conditions and risk assessment using the hazard analysis at a feed materials storage facility in Japan. This study will consider implications for the feed industry because the hazard analysis clarified the sites of Salmonella contamination, the tendency of contamination and the points for implementing control measures in the feed materials storage facility.

[Case Study:Identification of Microbial Distribution and Contamination Source by PDCA Cycle at a Boiled Noodles Factory].

Boiled noodles are considered to be one of the most perishable foods due to their high moisture content and high water activity. Thus, the hygiene control measures based on HACCP manuals has been recommended in the noodle manufacturing industry. However, there were several cases in which post-packaged products manufactured at the Boiled noodles factory of small-to-medium size company detected a viable cell count higher than their voluntary standards. To identify the source of microbial contamination, an investigation based on the Plan-Do-Check-Act (PDCA) cycle was conducted. The results showed that the bacteria causing the contamination were environmental bacteria. Secondary contamination occurred during the cooling process after sterilization. Airborne environmental bacteria and oxygen may have been introduced into the rinsing and cooling water tank by the strong water flow during the rinsing and cooling process, inducing growth of microorganisms in the cooling water and contaminating the final product. This is a new finding, as such occurrence was not listed in the HACCP manual and should be contributed to plan HACCP system.