Substituting Natural Honey for Cane Sugar (Sucrose) Retards Microbial Growth Independent of Water Activity During Storage of Tomato Jam

Abstract

Today, there are several attempts to make nutritious food products low in glycemic carbohydrates as this can partly help in solving the ever-growing numbers of type 2 diabetes and obesity. We thus made two types of jam, one using conventional sucrose with a high glycemic index and the other using honey which is regarded as a low glycemic index carbohydrate. Honey jam had comparable physical properties with sucrose jam. The total soluble solid (Brix) was significantly lower in honey jam than in sucrose jam (p=0.04) indicating less sugar in honey jam. Both jams had comparatively higher percent moisture content than other jams reported in literature potentially suggesting reduced storage stability. Despite having higher water activity, honey jam had progressive decrease in microbial colony counts suggesting honey was inhibitory to growth of microorganism compared to sucrose jam. This effect was independent of water activity as sucrose jam which had lower water activity promoted growth of microorganism during storage. Therefore, substituting natural honey for sucrose during formulation of tomato jam retards microbial growth thereby prolonging shelf life.