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technologies is the high hydrostatic pressure (HHP). Nutritionally, it enhances the intake of dietary nutrients in human by converting the complex ones into smaller ones ( McInerney et al., 2007 ). Applications of HHP in food industries includes reduction in

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Progress in Agricultural Engineering Sciences
Authors:
István Dalmadi
,
Dávid Kántor
,
Kai Wolz
,
Katalin Polyák-Fehér
,
Klára Pásztor-Huszár
,
József Farkas
, and
András Fekete

High hydrostatic pressure (HHP) processing technology offers the possibility to preserve quality attributes. Objective test methods describing quality in a complex form have an important role in the development of new products and in the quality assurance of different technologies. Therefore, research was performed to compare the effects of HHP treatment and heat pasteurization on visual appearance, volatile composition, taste and texture properties of strawberry purees measured by sensorial and objective methods. Sensory evaluation did not show significant differences between samples. Similar result was obtained from the color measurements. Viscosity of purees changed only slightly as a result of the treatments. Electronic nose and electronic tongue were found to be promising tools for discrimination of strawberry purees treated by different levels of high hydrostatic pressure or thermal treatment. Canonical discriminant analysis showed that control and “600 MPa for 5 minutes” samples were quite similar. Samples treated by 600 MPa for 15 minutes were distinguished from the above mentioned ones. The heat treated samples (80°C for 5 and 15 minutes) were definitely separated from the control samples. Fusion of the data from the electronic nose and tongue showed the same trend and improved the classification of the treated puree samples.

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, at 100 °C (Lainox VE051P) M Microwave oven treated for 3 min at 85 ºC, 100 W, A3 (vegetable mode) H HHP treated for 3 min at 20 ºC, 300 MPa (Resato B2441) U UV light treated for 15 min at 20 ºC, Power: 30 W, 312 nm (VL-115.M) Fig. 1. Images of the

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Abstract  

High hydrostatic pressure (HHP) has been investigated as an alternative to thermal processing for food preservation. HHP has been known to affect high molecular weight polymers causing phase change. Starch is gelatinized at a pressure on the order of 600–700 MPa, at 25 °C. Gelatinized starch recrystallizes during storage affecting the texture and shelf life of food products. The effect of HHP processing on the crystallization of starches from different botanical origins during storage at 4 and 23 °C was investigated. Crystallization kinetics of HHP treated wheat and corn starch gels were compared using DSC. The effect of crystallization on structure was evaluated in terms of storage modulus. The rate of retrogradation depended on the storage temperature (23 °C and 4 °C) and the botanical origin of the starch. The least crystallization was observed in HHP treated wheat starch stored at 23 °C. The storage modulus increased with crystallization of starch.

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Abstract  

The thermal degradation characteristics of head-to-head poly(styrene) [HHPS] should provide insight with respect to the impact of head-to-head placement on the thermal stability of traditional atactic head-to-tail polymer [HTPS]. The synthesis of head-to-head poly(styrene) must be accomplished indirectly. The head-to-head polymer is most satisfactorily obtained by dissolving metal reduction of poly(2,3-diphenyl-1,3-butadiene) [PDBD] generated by radical polymerization of the corresponding diene monomer. Full saturation of the polymer mainchain requires several iterations of the reduction procedure. Since the decomposition of poly(2,3-diphenyl-1,3-butadiene) is prominent at 374C and that for head-to-head poly(styrene) is similarly facile at 406C, it seemed feasible that TG of partially hydrogenated PDBD might be utilized as a convenient means of monitoring the extent of hydrogenation. This has been demonstrated for various levels of unsaturation remaining - from approximately 90 to less than 10%. Within this range the peak areas from the DTG plots of the partially hydrogenated polymer provide a good reflection of the ratio of unsaturated to saturated units in the polymer. Even low levels of unsaturation in the polymer may be detected by the asymmetry of the decomposition peak for the polymer.

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. Dispos. 2008 36 1088 1096 B. Li, T. Zhang, Z. Xu, H.H.P. Fang , Anal. Chim. Acta

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SBA-15 silicas containing sucrose

Chemical, structural, and thermal studies

Journal of Thermal Analysis and Calorimetry
Authors:
M. Barczak
,
M. Oszust-Cieniuch
,
P. Borowski
,
Z. Fekner
, and
E. Zięba

. 14. Yiu , HHP , Wright , P , Botting , NP 2001 Enzyme immobilisation using SBA-15 mesoporous molecular sieves with functionalised surfaces . J Mol Catal B 15 : 81 – 92 10.1016/S1381-1177(01)00011-X

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