Qualitative Assessment of Frying Oil and Microbial Analysis of Fast Foods on Public Health Perspective

Abstract

One of the most popular methods of food preparation is frying. Since in fast food restaurants the oil is heated for prolonged and repeated periods of time, toxic compounds in oils likely go up to very high concentrations. In-use frying oils were collected from ten randomly selected restaurants in Chattogram city, Bangladesh .In this study, we investigated chemical quality of oils that was used for frying in fast food restaurants and analyzed microbial load of some types of fast food on public health perspective. The chemical properties of frying oils were determined as saponification value, peroxide value, acid value, and iodine value. A significant difference (P<0.05) was found in all characteristic parameters of different oil samples. The highest saponification value of frying oil was found in sample 9 (264mg KOH/g) in the evening period and lowest value was found in sample no.10 (203.43mg KOH/g) in morning period. The range of peroxide value was between 14.25-29.58 meq O2 /kg in morning and in evening it was between 15.09-30.53 meq O2/kg. Sample 4 had the highest acid value (5.67 mg KOH/g) in evening and sample 2 had the lowest acid value (1.60 mg KOH/g) in morning. Changes in iodine value for the collected samples of the used frying oil was significantly decreased. The highest iodine value in the morning was in sample 6 (35.04g I2 /100g) and in evening the value was (34.40g I2/100g). Codex standard for iodine value is 50-55 g I2 /100g for palm oil.Taking consideration of all parameters the study concluded that evening frying oil had lower quality than morning samples. The colony forming unit of microbiological sample indicates that some brand of fast food shop burger and sandwich has much bacterial load that indicates those brand of fast food is harmful for human health.