ARS | Publication request: Characteristics of extraction and functionality of protein from tomato pomace produced with different industrial processing methods

Submitted to: Food and Bioprocess Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 16, 2013
Publication Date: February 4, 2013
Repository URL: http://dx.doi.org/10.1007/S11947-013-1057-0
Citation: Shao, D., Atungulu, G.G., Pan, Z., Yue, T., Zhang, A. 2013. Characteristics of extraction and functionality of protein from tomato pomace produced with different industrial processing methods. Food and Bioprocess Technology. DOI: 10.1007/S11947-013-1057-0.

Interpretive Summary: Tomato processing generates a large amount of tomato pomace as a by-product which contains a high percentage of seeds. The seeds could be a good raw material for producing nutritional and value-added food ingredients and products. Since the two typical hot and cold break processing methods may affect the properties of the seeds, this research studied the effect of the processing methods on protein extraction effectiveness and functionalities of seed meals and isolated protein products. The resulted showed that the seeds from hot break process had a lower protein extraction yield compared to cold break. Hot break process also significantly influenced protein related functional properties of the seed meals. The defatted seed meal from hot break process had higher water and oil absorption capacities, but lower emulsifying ability and stability (ES), and foaming capacity and stability (FS) compared to that from cold break. The results indicated that the products from tomato seeds have a great potential to be used for human nutrition.

Technical Abstract: The seeds from tomato pomace, a by-product of tomato processing, contains valuable but underutilized protein with unique functional properties. The objectives of this research were to study the impact of industrial hot and cold break tomato processing on protein extraction from defatted tomato seeds and elucidate protein related functional properties of the defatted and non-defatted seed meals. Based on the results, hot break processing denatured protein and lowered yield of protein extracted from defatted hot break tomato seeds (DHTS) to 9.07% to 26.29% compared to 25.60% to 32.56% from defatted cold break tomato seeds (DCTS). Hot break processing also significantly influenced protein related functional properties of the seed meals. DHTS had higher water absorption capacity (WAC) of 8.87 g/g protein, and oil absorption capacity (OAC) of 6.06 g/g protein but lower emulsifying ability (EA) of 0.06 to 0.71, emulsifying stability (ES) of 9.07 to 28.13 min, foaming capacity (FC) of 4.00 to 20.53 %, and foaming stability (FS) of 0.50 to 30.17 min compared with DCTS. The corresponding WAC, OAC, EA, ES, FC, and FS values of DCTS were 8.08 g/g protein, 5.71 g/g protein, 0.08 to 0.95, 11.76 to 36.94 min, 5.47 to 39.87%, and 0.50 to 61.00 min. Hot break tomato seeds (HTS), DHTS, and DCTS had higher bulk density and WAC compared with commercial soy protein (SP). The FC and FS of tomato samples were inferior while the ES were superior to SP. The results indicated that product from tomato seeds have a great potential to be used for human nutrition.