Quality changes in frozen Brussels sprouts during storage. II. Objective quality parameters: texture, colour, ascorbic acid content and microbiological growth

Brussels sprouts were stored at –18°C, –9°C and –4°C. During this storage, the colour of whole Brussels sprouts and Brussels sprouts slurry, measured as the greenness (Hunter –a value), decreased, probably can be described as a first order decay. The reflection at 680 nm of Brussels sprout slurry measures possibly the constant sum of chlorophyll and pheophytin. This can be a useful indication of the initial colour of the product. Also the ascorbic acid content can be a useful quality index, provided the initial level is known. Although not a very sensitive one, the shear force seems to be the most reliable textural parameter. From microbiological point of view, a storage temperature of –18°C as well as –9°C, is quite acceptable.