Study On The Method And Technique For Patulin Degradation

Patulin is a neurotoxic secondary metabolite of fungi, which has potential carcinogenic and teratogenic effects. The major dietary exposure of humans to patulin is from the consumption of apple and apple juice contaminated by molds. Patulin is the most stable in apple juice, and is one of important quality criteria for apple juice. Therefore, many countries and some international organizations have paid much attention to patulin. Patulin is difficult to eliminate completely in the process of apple juice production so that it could exceed the limits in apple juice, which is one of the main causes that can block the exports of Chinese apple juice. At present, majority of apple juice producers adopt resin adsorption for patulin elimination. This method is an effective measure to control patulin concentration, but it can enrich patulin in the resin, which has constituted a potential threat to environment. So studying and developing new environment-benefiting, safe, economical, efficient and practical patulin degradation techniques has paramount value on society and research.The patulin degradation after ultralsonic wave treatment and 60Co-γray irradiation treatment in pH4.0 acidic water acidified by acetic acid and clear apple juice with certain content patulin were studied systematically in this paper. The accumulation situations of Pat degradation product under the two treatments were identificated initially by analyzing and reading the HPLC peak area atlas of Pat in acidic water in this paper. Besides, this paper also studied the influences of two thiol group Substances (reduced glutathione andβ–Lactoglobulin ) to patulin content in clear apple juice and pH4.0 acidic water acidified by acetic acid separately. The main experiment results are as the following:1. Ultrasonic wave can degrade patulin in pH4.0 acidic water acidified by acetic acid ( initial concentration 1.300mg/L ) greatly,but it has no effort on patulin in clear apple juice ( initial concentration 1.356mg/L ). The degradation capability of ultrasonic wave to patulin is closely connected with power and treatment time of ultrasonicwave:①The best ultrasonic generator power for patulin degradation in pH4.0 acidic water was 600W. 80% patulin in acidic water was degraded after 180 min under this treatment, and no Pat degradation by-products was investgated during HPLC determination for Pat residue in acidic water;②The degradability of patulin was raised with the increase of treatment time.2. 60Co-γray can degradate patulin effectively both in pH4.0 acidic water acidified by acetic acid and clear apple juice. The capability of this method for patulin degradation was raised with the increase of irradiation dose, but the capability in clear apple juice was weaker than in acidic water obviously when the irradiation dose was same. The result of HPLC determination for Pat residue in acidic water showed: there is no other by-products in Pat acidic water (acidified by acetic acid) solution after irradiation treatment, meanwhile the contents of other extraneous constituents in acidic water besides patulin also had been reduced obviously by irradiation. Irradiation can result in obvoious decrease of soluble solids and amino-acids content, increasing of colour value and fading of color in apple juice, decrease of sugar and D-malic acid content.3. Reduced glutathione (GSH) andβ–Lactoglobulin (β-Lg) both can degradate patulin in clear apple juice, but the time for Pat degradation were long. There was no obvious decrease of Pat concentration during 10 days after adding GSH andβ-Lg in clear apple juice . However,β-Lg is considered to be unsuitable to Pat degradation in apple juice for its addition can cause great thickness happened rapidly in clear apple juice. The Pat degradation in Pat acidic water (acidified by acetic acid) solution caused by GSH addition was dealt with by variance analysis way, the reasults showed that GSH acting concentration and the acting time between GSH and Pat both are extremely remarkable: The GSH solutions with certain GSH concentration(0.1,0.2mg/mL) can degradated Pat in acidic water effectively and rapidly, but 0.2mg/mL GSH, which can enable the Pat in acidic water (initial concentration 1.300mg/L) to degradate completely in 1day, had faster degrading speed than 0.1mg/mL GSH to patulin. Otherwise, Prolongling the acting time between GSH and Pat also can improve the Pat degradability with the same GSH acting concentration((﹥0.01mg/mL)).