Influence of different Freezing and Thawing condition on Texture, Colour and Sensory Parameters of Osmo-convectively Dehydrated Carrot Slices

Author: T.D. Kumavat, P.G. More and S.B. Jadhav

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Abstract

Carrot (Daucus carota L.) is very popular root crop, cultivated throughout the world. Being rich in bioactive compounds like carotenoids and other nutrients, carrot has an important place in human diet. Pre-treatment prior to processing helps to prevent the loss in nutritional, sensorial, textural and functional properties of dehydrated fruits and vegetable. Texture, colour and sensory parameter play an important role in consumer acceptance of dehydrated ready to eat products. In most of the earlier studies, carrot was osmo-dehydrated without freezing pretreatment and dried products were used after rehydration. During freeze thaw pretreatment, temperature and time of freezing and thawing plays an important role in final quality of osmo-dehydrated products. Considering the influence of freeze-thaw treatment on texture and colour of osmo-dehydrated product, the present investigation was carried out to assess the effect of freezing and thawing time on objectives and subjective evaluation of colour and texture osmo-convectively dehydrated carrot slices and also on overall acceptability of products. Blanched carrot slices were frozen -25 oC freezing temperature for 12 and 24 h duration. Thawing of frozen carrot slices was carried out at low and ambient temperature condition for 2 and 8 h duration. The effect of freezing and thawing duration on texture and colour of dried carrot slices were objectively evaluated in terms of hardness and L*, a*, b* value of colour. Also, subjective evaluation was carried out by using 9-point scale to assess the overall acceptability of osmo-convectively dehydrated carrot slices. It was found that hardness of osmo-convectively dehydrated carrot slices influenced by freezing and thawing time for both thawing condition. Subjective and objective evaluation of osmo-convectively dehydrated carrot slices showed higher the retention of colour in pre-frozen osmo-convectively dried carrot slices for 24 hours irrespective of thawing duration. Also non-significant difference was observed in hardness and colour values for 12 and 24 h freezing time. Osmo-convectively dehydrated carrot slices prepared by using 12 hours freezing time and 8 h thawing at low temperature condition obtained higher overall acceptance.

Keywords

Freezing, Osmotic dehydration, Colour, Hardness, Overall acceptability

Conclusion

Hardness and colour of osmo-convectively dehydrated carrot slices was decreased with increased with increasing freezing and thawing time for both low and ambient thawing condition. According to subjective and objective evaluation, osmo-convectively dehydrated carrot slices prepared with 12 hours freezing and 8 h thawing time at low temperature condition obtained higher overall acceptance.

References

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How to cite this article

T.D. Kumavat, P.G. More and S.B. Jadhav (2023). Influence of Different Freezing and Thawing condition on Texture, Colour and Sensory Parameters of osmo-convectively Dehydrated Carrot Slices. Biological Forum – An International Journal, 15(2): 609-613.