Skip to main content
ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #323125

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

Location: Healthy Processed Foods Research

Title: Demonstration tests of infrared peeling system with electrical emitters for tomatoes

Author
item Pan, Zhongli
item Hamed, M. El-mashad - University Of California
item Li, Xuan - University Of California
item Khir, Ragab - University Of California
item Atungulu, Griffiths - University Of Arkansas
item Zhao, Liming - University Of Shanghai
item Kuson, Pramote - King Mongkut'S Institute Of Technology Ladkrabang
item Mchugh, Tara
item Zhang, Ruihong - University Of California

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2016
Publication Date: 8/29/2016
Citation: Pan, Z., Hamed, M., Li, X., Khir, R., Atungulu, G., Zhao, L., Kuson, P., McHugh, T.H., Zhang, R. 2016. Demonstration tests of infrared peeling system with electrical emitters for tomatoes. Transactions of the ASABE. 59(4):985-994. doi: 10.13031/trans.59.11728.

Interpretive Summary: California produces more tomato products than any other states in the U.S. Peeled tomatoes can be processed into many products such as whole peeled tomato, tomato puree, tomato paste, juice, powder, sauce, ketchup, and chip. Steam and lye are commonly applied methods for peeling of tomatoes and other fruits and vegetables. Despite its wide application, the sustainability of lye peeling is currently a concern because it produces wastewater with high pH and salt contents. The wastewater produced needs costly treatments before discharge to surface water. Even though steam-peeling method does not have salt problem, it needs large amounts of water and energy, which increases the cost of final products. The objectives of this study were to: (1) conduct on-site tests in commercial tomato processing plants to evaluate the performance of the IR dry-peeling equipment and technology; (2) conduct side-by-side comparison of product quality between IR dry-peeling and commercial steam peeling methods; and (3) estimate the energy consumption for a full-scale IR dry-peeling process. The IR dry-peeling technology has been successfully demonstrated by a pilot scale peeling system at two commercial tomato processing facilities located in California. The demonstration results showed that the IR dry-peeling technology could be a viable alternative to lye and steam peeling.

Technical Abstract: Infrared (IR) dry-peeling is an emerging technology that could avoid the drawbacks of steam and lye peeling of tomatoes. The objectives of this research was to evaluate the performance of an IR peeling system at two tomato processing plants located in California and to compare product quality, peelability and energy consumption of IR and steam peeling. The system was continuously operated using tomatoes of different sizes and cultivars. High percentages (62%-85%) of fully peeled tomatoes were obtained and varied depending on tomato cultivars and the seasonality. IR dry-peeled tomatoes had a firmer texture than steam peeled ones. IR peeling achieved a peeling loss in the range of 17% - 42% that was lower than typical loss in the industry. Small tomatoes had higher loss than large tomatoes in the late season. Prediction of the thermal energy consumption of the technology in a 10-ton/h full-scale production is to be at 117.0 and 137.3 MJ/ton for an indoor or outdoor operation, respectively. The estimated energy savings of IR dry-peeling operation should be 22% and 28% compared to lye and steam peeling, respectively. The demonstration results showed that the IR dry-peeling technology could be a viable alternative to lye and steam peeling.