Effect of Spices on the Growth of Aspergillus flavus and Aflatoxin B1 Production

Since the discovery of AFB1 as an important mycotoxin in 1960, several investigations have attempted to develop methods for the degradation and removal of mycotoxins from food and feed. The use of chemical preservatives in food to abate the mycotoxin problem has disadvantages due to residual effects of these preservatives on human and animal health (Freedman 1980; Parke and Lewis 1992; Knezevic and Serdar 2009). On the other hand, the use of natural products is considered to be safe for humans and the environment. Several studies on antimicrobial and antioxidant properties of plants, spices and their essential oils have been reported (Patikar et al. 1993). Herbs and spices such as cinnamon, clove, mustard, thyme and allspice are also well documented to possess strong antimicrobial properties (Hitokoto et al. 1980; Zaika 1988). Extracts from garlic and carrot (Thanaboripat et al. 1997) have been reported to have antifungal and anti-aflatoxigenic properties. The essential oils of Cinnamomum jensenianum (Tian et al. 2011), Ocimum sanctum (Kumar et al. 2010), Zataria multiflora (Gandomi et al. 2009), Syzygium aromaticum (Pinto et al. 2009), Chenopodium ambrosiodes (Kumar et al. 2007), Cymbopogon citrates (Paranagama et al. 2003), etc. were studied for inhibiting the growth of toxigenic Aspergillus and production of AFB1. Eugenol and cinnamaldehyde, which are the main components of clove and cinnamon oil, have been reported to inhibit AFB1 production (Bullerman et al. 1977). Most of the published data deals with essential oils and extracts of herbs and spices. There is scope for studying the effect of whole spices on growth of fungi and mycotoxin synthesis. The spices cinnamon, cardamom, star anise and clove are commonly used as ingredients in many Indian cuisines for their flavour, aroma and as preservatives. Therefore, they were used in the present study.