Analysis of heat transfer characteristics of postharvest heat treatment conditions of fruits and vegetables
DING Yuxian1,2, ZHANG Na1,2*, CHEN Aiqiang3
1(College of Civil and Architecture, East China of Jiaotong University, Nanchang 330013,China); 2(National Experimental Teaching Demonstration Center of Civil Engineering, East China Jiaotong University, Nanchang 330013, China); 3(Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin 300134, China)
Abstract: This study is to explore the relationship between hot water treatment conditions and heat transfer characteristics of fruits and vegetables. Using computational fluid dynamics, heat transfer simulation was performed on a variety of fruits and vegetables (apple-pear, mango, navel orange, strawberry, grape and cucumber) with known heat treatment conditions, and the heat transfer rate and temperature distribution of the pulp center were obtained. The results show that the rms error between the simulated value and the experimental value of the heat transfer model is 7.8%, and the accuracy is high. Based on the analysis of the principles of fruit and vegetable storage and transportation, it′s known that the heat preservation effect is closely related to the characteristics of fruit types. For some varieties with strong storability, the heat transfer rate only needs to be in the rising stage under heat treatment conditions, (such as apple pear: 0-0.7; navel orange: 0-0.55), but if the storability is average or poor, the heat transfer rate needs is in a falling zone or tends to level (such as mango 2.7-0.5; cucumber 1.1-0.3 or strawberry 0.3-0; grape 1-0), so that the energy exchange is sufficient and the heat transfer effect is enhanced. "Low temperature and long time" or "High temperature and long time" treatments have the best heat transfer effect, but low temperature time and high temperature thresholds should be considered to prevent thermal damage. This method provides a theoretical reference for exploring the range of heat treatment conditions for other varieties.
MAXIN P, WILLIAMS M, WEBER R W S.Control of fungal storage rots of apples by hot-water treatments: A Northern European perspective[J]. Erwerbs-Obstbau, 2014, 56(1):25-34.
[2]
DI FRANCESCO A,MARI M, ROBERTI R.Defense response against postharvest pathogens in hot water treated apples[J]. Scientia Horticulturae, 2018, 227:181-186.
[3]
ZHANG Z K,GAO Z Y,LI M,et al.Hot water treatment maintains normal ripening and cell wall metabolism in mango (Mangifera indica L.) fruit[J].Hort Science,2012,47(10):1 466-1 471.
[4]
NASEF,IBRAHIM N.Short hot water as safe treatment induces chilling tolerance and antioxidant enzymes, prevents decay and maintains quality of cold-stored cucumbers[J].Postharvest Biology and Technology,2018,138:1-10.
[5]
AMER, BAHER M A, AZAM,MOSTAFA M. Using hot water as a pretreatment to extend the shelf life of cucumbers (Cucumis sativus L.) under cold storage conditions.[J].Journal of Food Process Engineering,2019,42(2):1-11.
[6]
WU Z M, YUAN X Z,LI H,et al.Heat acclimation reduces postharvest loss of table grapes during cold storage-Analysis of possible mechanisms involved through a proteomic approach[J]. Postharvest Biology & Technology, 2015,105:26-33.
[7]
陈瑶.热处理对柑橘果实采后保鲜效果的研究[D].南昌:江西农业大学, 2014.
[8]
CHEN A Q,YANG Z,YIN H J,et al.Preservation quality of cold shock treated cucumber and heat transfer characteristic during treatment[J].Transactions of the Chinese Society of Agricultural Engineering, 2011, 27(11):349-353.
ANWAR R,MALIK A U.Hot water treatment affects ripening quality and storage life of mango (Mangifera indica L.)[J]. Pakistan Journal of Agricultural Sciences, 2007, 44:304-311.
[13]
BOTANY C.Control of post-harvest fungal diseases of tropical fruits by heat treatment: A review[J]. Current Botany, 2012.
[14]
KANESIRO M A B,DURIGAN J F, Faleiros R R D S,et al. Postharvest treatments on quality of mango fruits (Mangifera indica L var. Zill) stored at low temperature[M]. Developments in Food Engineering. Springer US, 1994.
SABIR F K,SABIR A.Quality response of table grapes (Vitis vinifera, L.) during cold storage to postharvest cap stem excision and hot water treatments[J]. International Journal of Food Science & Technology, 2013, 48(5):999-1 006.
FENG X,HANSEN J D,BIASI B,et al. Use of hot water treatment to control codling moths in harvested California ‘Bing’ sweet cherries[J]. Postharvest Biology and Technology, 2004, 31(1):41-49.