Carrot, thermal processing

Among thermal processes, canning caused the largest trans-to-cis isomerization of provitamin A carotenoids, increasing the total cis isomers by 39% for sweet potatoes, 33% for carrots, 19% for collards, 18% for tomatoes, and 10% for peaches 13-di-P-carotene was the isomer formed in highest amonnts. ... 

Marx, M., M. Stuparic, A. Schieber et al. 2003. Effects of thermal processing on tran.v-f/.v-isomcrization of (3-carotene in carrot juices and carotene-containing preparations. Food Chem. 83 609-617. 

A C30 RP column has been applied for the separation of carotenoids present in various matrices such as human serum, raw and thermally processed carrots, a Duniella algae-derived preparation and a poultry feed. Samples were mixed with deionized water and CaC03, homogenized and extracted with acetone-hexane (1 1, v/v). 

Sila, D., Smout, C., Vu, S., and Hendrickx, M. (2004). Effects of high-pressure pretreatment and calcium soaking on the texture degradation kinetics of carrots during thermal processing. / Food Sci. 69, E205-E211. 

Canet, W., Espinosa, J. (1984). The effect of blanching and freezing rate on the texture of potatoes, carrots and peas, measured by mechanical tests. In P. Zeuthen, J. C. Cheftel, C. Eriksson, M. Jul, H. Leniger, P. Linko, G. Varela (Eds.), Thermal Processing and Quality of Foods (pp. 678-683). Elsevier Applied Science, London. 

Fig. 11 HPLC of carotenoids solvent-extracted from (A) raw and (B) thermally processed carrots. Column, 5-/um polymeric C1(J (250 X 4.6-mm ID) mobile phase, methyl tert-butyl ether/methanol (11 89), 1 ml/min absorbance detection, 453 nm. Tentative peak identifications (1) all-trans-lutein (2) 13-cis-a-carotene (3) a cis-a-carotene isomer (4) 13 -cA-a-carotene (5) 15-cis-/3-carotene (6) 13-cis-/3-carotene (7 and 8) cis-fi-carotene isomers (9) all-frans-a-carotene (10) 9-cis-a-carotene (11) all-frans-/3-carotene (12) 9-ci. -/3-carotene. (Reprinted with permission from Ref. 192. Copyright 1996, American Chemical Society.)...

OGUNLESi A T and LEE c Y (1979), Effect of thermal processing on the stereoisomerisation of major carotenoids and vitamin A value of carrots , Food Chem, 4, 311-318. 

Nguyen, L.T., Rastogi, N. K., and Balasubramaniam, V.M. 2007. Evaluation of instrumental quality of pressure-assisted thermally processed carrots. Journal of Food Science 72 E264-E270. 

Rastogi, N.K., Nguyen, L.T., and Balasuhramaniam, V.M. 2008a. Effect of pretreatments on carrot texture after thermal and pressure-assisted thermal processing. Journal of Food Engineering 88 541-547. 

Figure 7. Color change of carrot puree due to the thermal processing. Color attribute L, a, and b are presented in the graph.

The results from the study of processed salty carrots suggested that the external color of the salty carrot samples is related to the extent of thermal processing (Table 4). The results also indicate that Aa is the parameter that correlates stronger... 

Figure 11. The a - and 6-carotene carotenes concentrations degradation of salty carrots due to the thermal process as functions of time at a temperature of 255 F.

Our research results also have demonstrated the feasibility of using CMV as a fast, non-destructive, in-line/on-line color sensor for a closed-loop controlled food process to produce high color quality food products. CMV was used, indirectly, to relate sensory panel perceived color quality and major pigment contents in food systems during diermal processes. The correlations between CMVS measured colors and human perceived colors of selected food models were established chemical markers were identified for color changes in thermal processes the correlations between external colors and principal pigment contents were established for two model food systems carrots and reformed beef cube. 

An example of this approach is shown with carrots (19). Seventeen cultivars of carrots were sliced transversely and blanched 4 min at 212F or 165F, then canned and processed 23, 30,45,60,75 min at 250F. The firmness of the phloem tissue and xylem tissue (core) were separately measured by a puncture test. Figure 5 shows log firmness versus process time for the cultivar Dominator Sunseed together with the equations for the lines of best fit and the correlation coefficients R. Similar plots were obtained for the other sixteen cultivars. Sufficient data was obtained to measure substrate "b" and the thermal firmness value. No data were collected to measure substrate "a" because it is not needed. However, the firmness at zero process time was measured and these points are plotted on the ordinate. The correlation coefficients range from r = 0.98 to r = 1.00 which shows the excellent fit of the empirical data to the kinetic model. 

Patras, A., Brunton, N.P, Pieve, S.D., Butler, F., and Downey, G. 2009b. Effect of thermal and high pressure processing on antioxidant activity and instrumental color of tomato and carrot purees. Innovative Food Science and Emerging Technologies 10 16-22. 

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