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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #287682

Research Project: New Sustainable Processing Technologies to Produce Healthy, Value-Added Foods from Specialty Crops and their Co-Products

Location: Healthy Processed Foods Research

Title: Separation methods and chemical and nutritional characteristics of tomato pomace

item Shao, Dongyan
item Atungulu, Griffiths
item Pan, Zhongli - John
item Yue, Tianli
item Zhang, Ang
item Chen, Xi

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2012
Publication Date: 2/1/2012
Citation: Shao, D., Atungulu, G.G., Pan, Z., Yue, T., Zhang, A., Chen, X. 2012. Separation methods and chemical and nutritional characteristics of tomato pomace. Transactions of the ASABE. 56(1):264-268.

Interpretive Summary: In order to identify the potential uses of the tomato pomace, it is vital to study its chemical and nutritional characteristics and develop effective method for separating peel and seed from the pomace. The results of this research revealed that all pomace samples, regardless of differences in tomato varieties and processing methods, were rich in various nutrients. Separation methods could affect residual nutrients, yield and purity of peel and seed from pomace. Both the dry and wet separation methods were effective to achieve separation of the studied pomace. However, the wet separation led to loss of important micronutrients due to nutrient leaching. In addition to the observed micronutrient loss, the wet separation method is also expected to be water intensive and could pose wastewater disposal problems. Therefore, dry separation is recommended as a more promising method for achieving effective separation of tomato pomace. This research indicated that tomato pomace has a great potential to be used as a resource of high value components utilizable for human nutrition.

Technical Abstract: Tomato processing generates a large amount of pomace as a low value by-product primarily used as livestock feed or disposed. The objectives of this research were to investigate the chemical and nutritional characteristics and determine effective separation methods of peel and seed of commercial tomato pomace from hot and cold break processes. The chemical composition of pomace and nutritional quality including fatty acid of the seed oil and amino acid profile of defatted seed were determined, respectively. The impacts of dry and wet separation on physicochemical properties of peel and seed of pomace were evaluated. Based on the results, studied pomace samples were rich in nutrients: 8.37%-16.24% fat, 15.08%-22.70% protein, 48.49%-64.75% insoluble dietary fiber (IDF), 8.91%-10.04% soluble dietary fiber (SDF), and 98.16-172.07 mg/kg lycopene. The seed oil had total unsaturated fatty acid content up to 80.10% and the defatted tomato seed contained six kinds of essential amino acids with Histidine, an essential amino acid for infants, as the most dominant (23.34%). Both the dry and wet separation methods were effective to achieve separation of the studied pomace. However, wet separation caused significant loss of micronutrients. The study indicated that commercial tomato pomace can be separated without water and used to produce value-added products with high nutrients.