The impact of raw material selection for fresh-cut quality - with carrots as an example

The quality of raw material for fresh-cut production is very important. In the industry, carrots for processing are mainly selected on the basis of appearance and texture, and washed roots free of defects are used for minimal processing. Whole carrots change quality after harvest even though they are harvested mature and stored at low temperatures. To provide fresh-cut carrots with a consistent high quality, a supply of stored carrots with specific quality attributes are needed. The aim of the present study was to study the impact of the raw material quality on fresh-cut processing quality. Mature carrots stored for up to 6 month at 1°C and >95% relative humidity were used. The carrots had different physiological ages at processing. Two experiments were carried out: one experiment with long-term storage of whole carrots and a second experiment with long-term storage of whole carrots followed by processing. During cold storage of the unprocessed carrots, the respiration rate decreased, and the respiratory quotient (RQ) increased. Similar results were observed for fresh-cut carrots, but the magnitude of physiological ageing and senescence on respiration and RQ was greater. During cold storage, whole carrots also began to sprout. Sprouting began around 3 months after harvest increasing up to 25 and 82% after 3½ and 5½ months of storage, respectively. All fresh-cut products developed a sour-fermented flavour during 8 days storage at 5°C, however, this off-flavour was less pronounced in fresh-cut carrots made from freshly harvested roots. The results show that it is important to take physiological age of the raw material into account when selecting materials for fresh-cut production. It is suggested to use quality parameters such as sprouting and RQ among others in the selection of carrots for fresh-cut quality.