The Effects of Flaxseed Powder on Antioxidative, Microbial and Sensory Properties of Chocolate

In this research, the effects of fortification of chocolate samples with flaxseed at different levels of 0% (control treatment), 5%, 10%, 15% and 20% were assessed on the microbial properties, peroxide value and tocopherol content of chocolate samples during 3 months storage. Sensory attributes of chocolate samples were determined by fourteen trained panelists using 5-point Hedonic scale in 1st, 15, 30, 45 60, 75 and 90th days. It was observed that with increasing flaxseed content in chocolate samples, the mean content of gamma-tocopherols increased. The level of gamma tocopherols in control samples were 17.1 ppm, compared with 38.57 ppm in samples containing 20% flaxseed. Moreover, peroxide value showed an increasing trend with increasing flaxseed powder content. In addition, the highest peroxide value (1.875 meq/Kg) belonged to samples containing 20% flaxseed powder at the end of storage time and the lowest peroxide value (0.5 meq/Kg) was observed in control treatments in 1st day. However, all the peroxide values were in the standard range (max: 2 meq/Kg). Microbial enumeration of enterobacteriaceae, E. coli, salmonella, coagulase-positive staphylococci, yeast and molds were in the standard range during 90 days of storage. The maximum count of yeasts belonged to samples containing 20% flaxseed powder. With regard to the consumer acceptance, chocolate samples containing 5% and 10% flaxseed received higher sensory scores compared with other treatments and samples containing 20% flaxseed had the lowest sensory acceptance compared with control treatment. Consequently, the results indicated that by incorporating of flaxseed powder in chocolate, it is possible to produce functional product fortified with anti-oxidants that could have important role in the health of consumers.