Efficiency of anacardic acid as preservative in tomato products
Anacardic acid, 6[8′(Z), 11′(Z),14′-pentadecatrienyl] salicylic acid is the main active principle of Anacardium occidentale (Anacardiceae), the cashew. Cashew nut shell liquid (CNSL) contains approximately 70% anacardic acids, 18% cardol, 5% cardanol, and some other phenols and less polar substances. Because of the presence of anacardic acids, the CNSL exhibits potent antimicrobial activity. In view of this and the potent antimicrobial activity of anacardic acid observed in our previous study, the present study was planned to evaluate the anacardic acid isolated by us in our previous study as a food preservative. The effect of anacardic acid at 0.014% (w/w) was studied in tomato paste and tomato ketchup inoculated with 2 × 104 cfu/g of Staphylococcus aureus, Bacillus subtilis and Escherichia coli and stored at room temperature. Good activity was observed, as no viable growth after 28 days in both the products. Results showed that anacardic acid was active against both gram-positive and gram-negative bacteria. Results of the study indicated that anacardic acid can act as a potential preservative in tomato products and can be considered as an alternative natural preservative over the synthetic preservatives. When safeties of synthetic preservatives are questioned, natural substances of plant origin may appeal to the public. The anacardic acid isolated form cashew nut shell is present in cashew nut, which is being consumed by a number of people as a food material. So it is relatively safe to use as an alternate to the existing synthetic preservatives.