Ultrasound and microwave treatments preserved quality of a pepper-based hummus enriched in mustard sprouts

Abstract

Mustard sprouts were added to a red bell pepper-based hummus to enhance the content of glucosinolates and sulforaphane. Hummus samples with 2% of mustard sprouts (M) and without them (CTRL) were treated by ultrasounds −50 °C/35 kHz/12 min- (US) or microwaves −9 kW/35 s- (MW) to preserve quality and safety during 28 days at 4 °C. No processing treatment was used as control (C). No differences were found between CTRL and M regarding their proximate composition and physicochemical quality during shelf-life. US and MW treatments were able to reduce the spoilage microbial load by 1–4 log CFU g−1. The mean vitamin C content of the pepper-based hummus was higher than 400 mg AA kg−1, while the total glucosinolate and sulforaphane content was 10.5 mg kg−1 and 10–15 mg kg−1, respectively. US increased the sulforaphane content (∼10–24%) preserving vitamin C similarly to control samples. However, MW decreased vitamin C and sulforaphane content by 50–90%, while glucosinolate content was like that of untreated samples. Therefore, US processing seems an interesting tool to inhibit the microbial growth and maintain quality throughout shelf-life. However, further studies should be implemented to elucidate optimum processing conditions according to food matrices.