Prevalence of viable <i>Monascus</i> van Tieghem species in fermented Red Rice (Hong Qu Mi) at consumer level in Selangor, Malaysia

Abstract

Red rice is a fermented product consumed widely throughout Asian countries as food colorant, food flavour and food preservative. Fermentation of red rice is accomplished by inoculating individual or several Monascus species onto white rice grains during which time the fungal starters biosynthesize the intense red pigments which are subsequently assimilated into the final product. The present work was undertaken to establish the prevalence of viable Monascal fungal starters involved in red rice fermentation from red rice samples obtained at consumer level in Selangor, Malaysia by means of morphological characterization. Macromorphology examined the size and texture of colonies on growth plates, and colony growth rates while micromorphology assessed the size and shape of conidiospores and texture of conidiophores and hyphae. A total of 50 red rice samples were obtained from which isolation and characterization of Monascal fungal starters were performed. From the red rice samples, Monascus purpureus Went was found to be the key Monascal fungal starter from which the isolation frequency was 58% as compared to that of Monascus pilosus K. Sato which was 42%. No strain of Monascus ruber van Tieghem was isolated. Since 100% of red rice samples gave viable spores which germinated at favourable conditions, there is an elevated risk of citrinin contamination of the final product. Therefore, further mycological and toxicological analyses on fermented red rice are warranted to raise public awareness on consumption of red rice.