Rheological properties and stability of low-in-fat dressings prepared with high-pressure homogenized yeast

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• 作者：Valeria E. Fernandez^a ; Gonzalo G. Palazolo^a ; ^b ; ^{gpalazolo@unq.edu.ar} ; Natalia A. Bosisio^a ; Luis M. Martí ; nez^a ; Jorge R. Wagner^a ; ^b
• 关键词：Dressing ; High-pressure homogenization ; o/w Emulsions ; Rheological properties ; Stability ; Yeast
• 刊名：Journal of Food Engineering
• 出版年：2012
• 期刊代码：67_02608774
• 类别：abs
• 出版时间：July, 2012
• 卷：111
• 期：1
• 页码：57-65
• 文件大小：751 K

摘要

The aim of present study was to investigate the feasibility of application high-pressure homogenized (HPH) yeast aqueous dispersions with low nucleic acid content for the formulation of low-in-fat dressings. The HPH treatment (1500 bar, 3 passes) in alkaline medium improved the protein dispersibility (>50%). Emulsions were prepared using sunflower oil (12.0%or 25%w/w oil), xhantan/guar gums (0.5%w/w), modified starch (0-4.0%w/w), salt, sucrose, acidulants, EDTA, and antimicrobial agents. All emulsions (pH 3.97 卤 0.27; a_w = 0.97 卤 0.01), whatever the starch content, behaved clearly as pseudoplastic fluids in steady flow measurements. Moreover, as the frequency sweep measurements were made they also exhibited a weak gel behavior. Although the presence of starch produced an increase of mean particle size (D_3,2 values), the rheological parameters (consistency index, proportionality coefficient and coordination number) also increased, so that the starch contributes to reinforce the three-dimensional network formed by oil droplets, protein aggregates and other polysaccharides. Yeast dressings were stable to coalescence after 28 days of quiescent storage (7.0 卤 0.5 掳C) and only the highest starch concentration at 25%w/w oil was sufficient to maintain the stability of network.