Effects of ultrasound on glass transition temperature of freeze-dried pear (Pyrus pyrifolia) using DMA thermal analysis
- Authors: Islam, Nahidul , Zhang, Min , Liu, Huihua , Xinfeng, Cheng
- Date: 2015
- Type: Text , Journal article
- Relation: Food and Bioproducts Processing Vol. 94, no. (2015), p. 229-238
- Full Text: false
- Reviewed:
- Description: The effect of ultrasound pretreatment at various power (360 W, 600 W and 960 W, frequency 20 kHz) on the glass transition temperature of freeze dried pear (Pyrus pyrifolia) has been studied. DMA temperature plots were divided into four sections (A - glassy region, B - transition region, C - Rubbery plateau region and D - terminal region) with the aim to analyze their properties changed with sonication. Under the same freeze drying condition, with the increase in ultrasonic power, dried pear showed higher glass transition in terms of storage modulus, loss modulus and loss tangent peak. Also a decrease in a
Low oil French fries produced by combined pre-frying and pulsed-spouted microwave vacuum drying method
- Authors: Quan, Xiaojian , Zhang, Min , Fang, Zhongxiang , Liu, Huihua , Shen, Qiaosheng , Gao, Zhongxue
- Date: 2016
- Type: Text , Journal article
- Relation: Food and Bioproducts Processing Vol. 99, no. (2016), p. 109-115
- Full Text: false
- Reviewed:
- Description: French fries were prepared by a combined method of pre-frying and pulsed-spouted microwave vacuum drying (PSMVD). The impact of pre-frying and PSMVD on the quality (oil content, color, texture, microstructure and shrinkage in volume) of French fries was studied and the sample was compared with that of only vacuum fried ones. The results indicated that the French fries prepared by the combined method had lower oil content (25%, db) than that of vacuum-fried sample (40%). Other property analysis also showed that the combined technique processed samples exhibited comparable food texture and color to that of vacuum fried samples, and had a porous microstructure with relatively smaller pore size. It was concluded that the combined method of pre-frying and PSMVD could be an alternative method to produce high quality French fries with low oil content. © 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
The energy consumption and color analysis of freeze/microwave freeze banana chips
- Authors: Jiang, Hao , Zhang, Min , Liu, Yin , Mujumdar, Arun , Liu, Huihua
- Date: 2013
- Type: Text , Journal article
- Relation: Food and Bioproducts Processing Vol. 91, no. 4 (2013), p. 464-472
- Full Text: false
- Reviewed:
- Description: This study investigated the energy consumption of preparing banana chips by freeze drying (FD) and microwave freeze drying (MFD) methods. The results in this study showed that the energy consumption for 400 g fresh banana (about 95 g dried samples) by FD process and MFD process are about 35.73 × 10 6 J (9.92 kW h) and 21.76 × 106 J (6.57 kW h), respectively. Compared to the traditional FD process, MFD can save up to 35.7% energy and 40% drying time. Increasing the heating power in the secondary drying stage of MFD process had been confirmed to result in decrease in both the energy consumption and drying time. After increasing the microwave power in the secondary drying stage from 1.0 W/g to 1.5 W/g in MFD process, total energy consumption is about 18.12 × 106 J (5.56 kW h) and drying time can be reduced from 360 min to 270 min. The sensory evaluation of produced banana chips at different drying conditions (1.0 W/g, 1.5 W/g and 2.0 W/g) revealed that the sensory properties are acceptable by the customers except the 2 W/g microwave power dried product. Thus, the method that increased the heating powder in the secondary drying stage of the MFD process could potentially be an effective method to reduce the energy consumption without seriously sacrificing the color of the end product. © 2013 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
- Description: C1