Abstract

This study is part of a large comparative study of various pre-treatments used to improve the technological abilities of plants. This study is specifically designed to systematically analyze the intensification of vacuum drying of carrots using cellulase, pectinase and macerozyme as a way to change both structure and functional behavior. These enzymatic pretreatments resulted in major changes in porosity, drying time, capacity and rehydration kinetics and water activity. However, their effects were fundamentally different from physical pretreatments generally used to increase technological capability of drying carrots, such as Freezing/Thawing (FT) instantaneous controlled pressure drop (DIC), or Simple Steaming (SS). Thus, in enzymatic pretreatments no correlation was observed in terms of structure and functional characteristics. This completely contrasts with FT, DIC and SS as thermal/texturing pretreatments, where we found that functional properties strictly depend on structural modifications. Thus thermal/texturing pretreatment operations involve systematically a high correlation between porosity and the ability to dehydration and rehydration. The changes induced by the enzyme pretreatments were closely linked to irreversible microscopic changes of the polymer chains.

Keywords:

Carrot, cellulase, enzyme pretreatment, macerozyme, pectinase, vacuum drying,

References

1. Allaf, T. and K. Allaf, 2014. Instant Controlled Pressure Drop (D.I.C.) in Food Processing: From Fundamental to Industrial Applications. Springer, New York.
   CrossRef    
2. Barat, J.M. and R. Grau, 2016. Drying: Principles and Types. In: Encyclopedia of Food and Health. Elsevier, pp: 456-461.
   CrossRef    
3. Bayer, E.A., J.P. Belaich, Y. Shoham and R. Lamed, 2004. The cellulosomes: Multienzyme machines for degradation of plant cell wall polysaccharides. Annu. Rev. Microbiol., 58: 521-554.
   CrossRef    PMid:15487947    
4. Chaveron, H. and H. Adenier, 1980. Etude de la composition des matières grasses de coques de cacao en vue de leur valorisation. Compte Rendu de Fin D'étude DGRST 77.7.0591.
   
5. Chen, Z.G., X.Y. Guo and T. Wu, 2016. A novel dehydration technique for carrot slices implementing ultrasound and vacuum drying methods. Ultrason. Sonochem., 30: 28-34.
   CrossRef    PMid:26703199    
6. Debs-Louka, E., W. Sahyoun, H. Adenier, J.N. Barbotin, N. Louka, H. Chaveron, D. Thomas and K. Allaf, 1996. Déshydratation de la carotte (Daucus carota L.): Effet d'un nouveau procédé sur les composés lipidiques et la microstructure = Drying of the carrot (Daucus carota L.): Effect of a new process on lipidic compounds and microstructure. Sci. Aliment., 16(5): 491-503.
   
7. Erenturk, S. and K. Erenturk, 2007. Comparison of genetic algorithm and neural network approaches for the drying process of carrot. J. Food Eng., 78(3): 905-912.
   CrossRef    
8. Gamboa-Santos, J., A.C. Soria, M. Villamiel and A. Montilla, 2013. Quality parameters in convective dehydrated carrots blanched by ultrasound and conventional treatment. Food Chem., 141(1): 616-624.
   CrossRef    PMid:23768402    
9. Karathanos, V.T., G. Villalobos and G.D. Saravacos, 1990. Comparison of two methods of estimation of the effective moisture diffusivity from drying data. J. Food Sci., 55(1): 218-223.
   CrossRef    Direct Link
10. Kuhad, R.C., R. Gupta and A. Singh, 2011. Microbial cellulases and their industrial applications. Enzyme Res., 2011: 1-10.
    CrossRef    PMid:21912738 PMCid:PMC3168787    
11. Mandels, M., R. Andreotti and C. Roche, 1976. Measurement of saccharifying cellulase. Biotechnol. Bioeng. Symp., 6: 21-33.
    
12. Massiot, P., X. Rouau and J.F. Thibault, 1987. Characterization of cell-wall polysaccharides of carrot. Food Hydrocolloid., 1(5-6): 541-544.
    CrossRef    
13. Massiot, P., X. Rouau and J.F. Thibault, 1988. Characterisation of the extractable pectins and hemicelluloses of the cell wall of carrot. Carbohyd. Res., 172(2): 229-242.
    CrossRef    
14. Mulet, A., A. Berna and C. Rossello, 1989. Drying of carrots. I. Drying models. Dry. Technol., 7(3): 537-557.
    CrossRef    
15. Negi, P.S. and S. Kumar Roy, 2001. The effect of blanching on quality attributes of dehydrated carrots during long-term storage. Eur. Food Res. Technol., 212(4): 445-448.
    CrossRef    
16. Sahyoun, W., F. Zerrouq and K. Allaf, 2016. Comparative study of various pre-treatments coupled to vacuum drying in terms of structural, functional and physical properties of carrot DaucusCarota. Int. J. Eng. Res. Sci., 2(2): 49-63.
    
17. Schwald, W., M. Chan, C. Breuil and J.N. Saddler, 1988. Comparison of HPLC and colorimetric methods for measuring cellulolytic activity. Appl. Microbiol. Biot., 28(4): 398-403.
    CrossRef    
18. Sharma, N., M. Rathore and M. Sharma, 2013. Microbial pectinase: Sources, characterization and applications. Rev. Environ. Sci. Biotechnol., 12(1): 45-60.
    CrossRef    
19. Wolff, J.P., 1968. Dosage des caroténoïdes totaux. In: Wolff, J.P. (Ed.), Manuel d'analyse des corps gras. 186, Azoulay, Paris.
    

Competing interests

The authors have no competing interests.

Open Access Policy

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Copyright

The authors have no competing interests.