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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 #323402

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

Location: Healthy Processed Foods Research

Title: Feasibility of Jujube peeling using novel infrared radiation heating technology

item WANG, BINI - Northwest University
item VENKITASAMY, CHANDRASEKAR - University Of California
item Pan, Zhongli
item HUANG, QINGYUAN - Northwest University

Submitted to: LWT - Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/31/2016
Publication Date: 2/3/2016
Citation: Wang, B., Venkitasamy, C., Pan, Z., Huang, Q. 2016. Feasibility of Jujube peeling using novel infrared radiation heating technology. LWT - Food Science and Technology. 69:458-467.

Interpretive Summary: Peeling is a key operation performed before direct consumption of jujube or further processing. Conventionally, mechanical, chemical and hot soaking peeling methods have been applied for jujubes. These peeling methods have adverse effect on product quality, are water and energy intensive, and pose serious salinity and wastewater disposal problems, resulting in considerable negative environmental impact. The infrared (IR) peeling method has shown advantages over conventional peeling methods with attractive merits such as uniform heating, high heat transfer rate, reduced processing time and energy consumption, and improved product quality and safety. Therefore, IR peeling was studied for peeling jujubes. Compared to the hot lye peeling, the IR dry peeling of jujube significantly reduced the peeling loss and color change. Therefore, it is considered as an effective peeling technique for the jujube skin removal with complete elimination of lye in the peeling process and reduced peeling loss, color change and processing time.

Technical Abstract: Infrared (IR) radiation heating has a promising potential to be used as a sustainable and effective method to eliminate the use of water and chemicals in the jujube-peeling process and enhance the quality of peeled products. The objective of this study was to investigate the feasibility of use IR heating as a dry-peeling method for jujubes. The rotating Li jujube fruits were heated using two electric IR emitters. The effects of IR radiation intensity (5.25–6.07 W/cm2), emitter distance (75–85 mm), and heating time (40–60 s) on the peeling performance of jujubes were investigated. Lye peeling of jujubes was used as a control. The operating parameters of the IR peeling system were optimized using response surface methodology (RSM). The heating with an IR intensity of 5.25 W/cm2 at the emitter distance of 75 mm for 56 s was found as the optimum condition resulting in the peelability of 96%, peeling easiness of 3.8 and moisture loss of 1.29% at jujube surface temperature of 115oC. The experimental results agreed well with those predicted by the models. The IR peeled jujubes had significantly low peeling loss and color change compared to lye peeled ones.