Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying

The quality changes of refined, bleached and deodorised palm olein (RBDPOo), soybean oil (SBO) and their blends during intermittent deep-fat frying at 180±5°C for 5h per day for 5 consecutive days were studied. The shelf-life of potato chips used for frying was also investigated. The results show...

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Main Author:	Liu, Jia Long
Format:	Thesis
Language:	English English
Published:	1999
Subjects:	Soy oil Deep frying Palm oil
Online Access:	http://psasir.upm.edu.my/id/eprint/8410/1/FSMB_1999_14_A.pdf
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id	my-upm-ir.8410
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spelling	my-upm-ir.84102012-11-09T01:37:29Z Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying 1999 Liu, Jia Long The quality changes of refined, bleached and deodorised palm olein (RBDPOo), soybean oil (SBO) and their blends during intermittent deep-fat frying at 180±5°C for 5h per day for 5 consecutive days were studied. The shelf-life of potato chips used for frying was also investigated. The results showed that the physicochemical properties of SBO were improved by blending with RBDPOo in terms of resistance to oxidation, iodine value (IV), anisidine value (AnV), foaming tendency, % polar component and polymers content. However, SBO also contributed to RBDPOo with respect to colour, viscosity, free fatty acids (FF A) content and smoke point. Sensory evaluation showed that potato chips fried in both of RBDPOo and SBO were equally preferred by the panellists. Shelf-life stability of the fried potato chips indicated that chips fried in RBDPOo were better than that fried in SBO. The blends of RBDPOo : SBO were improved with increasing proportion of RBDPOo. The observation showed that there were minimal effects on the rate of development of rancidity in the fried product beyond the fourth day of frying in all blends. The changes of RBDPOo with added TBHQ and (X-tocopherol during deep-fat frying were also studied. Addition of antioxidants resulted in improved oxidative stability. TBHQ was more effective in reducing the level of FF A, polar component and polymers and decreased the rates of change in IV and the ratio of C18:2/C16:0. (Xtocopherol was more effective in reducing AnV and totox values. However, adding antioxidants caused darkening of oils and increased the formation of foam during deep fat frying. Differential scanning calorimetry (DSC) was also used to monitor IV, peroxide value (PV), AV and FFA of frying oils. The heating thermogram was from -50 to 80°C at a heating rate of 5°C/min, whereas, the cooling thermogram was at the same rate from 80 to -50°C. Stepwise multiple linear regression (SMLR) analysis showed that peak characteristics, namely peak temperature, enthalpy and peak height of heating and cooling thermo grams can predict the parameters such as IV, PV, AV and FFA of the samples with the coefficient of determination (R2) at least 0.9300. Thus, this study showed that DSC method can monitor these quality parameters of fried oils to replace wet chemical methods which involve a large number of toxic and environmental unfriendly solvents and reducing the labour cost as well. Soy oil Deep frying Palm oil 1999 Thesis http://psasir.upm.edu.my/id/eprint/8410/ http://psasir.upm.edu.my/id/eprint/8410/1/FSMB_1999_14_A.pdf application/pdf en public masters Universiti Putra Malaysia Soy oil Deep frying Palm oil Food Science and Technology English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Soy oil Deep frying Palm oil
spellingShingle	Soy oil Deep frying Palm oil Liu, Jia Long Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying
description	The quality changes of refined, bleached and deodorised palm olein (RBDPOo), soybean oil (SBO) and their blends during intermittent deep-fat frying at 180±5°C for 5h per day for 5 consecutive days were studied. The shelf-life of potato chips used for frying was also investigated. The results showed that the physicochemical properties of SBO were improved by blending with RBDPOo in terms of resistance to oxidation, iodine value (IV), anisidine value (AnV), foaming tendency, % polar component and polymers content. However, SBO also contributed to RBDPOo with respect to colour, viscosity, free fatty acids (FF A) content and smoke point. Sensory evaluation showed that potato chips fried in both of RBDPOo and SBO were equally preferred by the panellists. Shelf-life stability of the fried potato chips indicated that chips fried in RBDPOo were better than that fried in SBO. The blends of RBDPOo : SBO were improved with increasing proportion of RBDPOo. The observation showed that there were minimal effects on the rate of development of rancidity in the fried product beyond the fourth day of frying in all blends. The changes of RBDPOo with added TBHQ and (X-tocopherol during deep-fat frying were also studied. Addition of antioxidants resulted in improved oxidative stability. TBHQ was more effective in reducing the level of FF A, polar component and polymers and decreased the rates of change in IV and the ratio of C18:2/C16:0. (Xtocopherol was more effective in reducing AnV and totox values. However, adding antioxidants caused darkening of oils and increased the formation of foam during deep fat frying. Differential scanning calorimetry (DSC) was also used to monitor IV, peroxide value (PV), AV and FFA of frying oils. The heating thermogram was from -50 to 80°C at a heating rate of 5°C/min, whereas, the cooling thermogram was at the same rate from 80 to -50°C. Stepwise multiple linear regression (SMLR) analysis showed that peak characteristics, namely peak temperature, enthalpy and peak height of heating and cooling thermo grams can predict the parameters such as IV, PV, AV and FFA of the samples with the coefficient of determination (R2) at least 0.9300. Thus, this study showed that DSC method can monitor these quality parameters of fried oils to replace wet chemical methods which involve a large number of toxic and environmental unfriendly solvents and reducing the labour cost as well.
format	Thesis
qualification_level	Master's degree
author	Liu, Jia Long
author_facet	Liu, Jia Long
author_sort	Liu, Jia Long
title	Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying
title_short	Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying
title_full	Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying
title_fullStr	Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying
title_full_unstemmed	Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying
title_sort	improvement of physicochemical properties of rbd palm olein blended with soybean oil for deep-fat frying
granting_institution	Universiti Putra Malaysia
granting_department	Food Science and Technology
publishDate	1999
url	http://psasir.upm.edu.my/id/eprint/8410/1/FSMB_1999_14_A.pdf
_version_	1747810800323526656

Improvement of Physicochemical Properties of RBD Palm Olein Blended with Soybean Oil for Deep-Fat Frying

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