PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

The prevalent saying that an apple a day keeps the doctor away may have much merit because of its valuable minerals, vitamins and antioxidant contents that benefit humans. However, because of the circulating news of apples being adulterated with formalin in Bangladesh, a considerable number of people are discouraged from consuming them. The research investigates the effect of formalin on the shelf life of apples. In this research, we have adulterated apples with three different concentrations (20%, 30%, 40%) of formalin and use three different methods to study the presence of formalin on the surface of the apples: (1) spectrophotometry, (2) a formalin test kit developed by the Bangladesh Council of Scientific and Industrial Research (BCSIR), and (3) an MS1100 gas sensor that functions as an E-nose. The test kit detection and spectrophotometry enabled the detection of the presence and the concentration of formalin on the apple, respectively. The E-nose is able to deduce the decay profile of formalin on the surface of the apples. The measurements showed the emission of formalin drops to their natural or pure form after approximately 30 hours. Formalin does not improve the shelf life of apples, and visibly, it arguably makes them appear less fresh. The phenomenon has also been explained by theory, which states that formalin primarily affects foods with relatively high protein content. Hence, shopkeepers who presumably use formalin do not benefit from its application.