排序方式: 共有4条查询结果,搜索用时 8 毫秒
1
1.
Arno C. Alting Fred van de Velde Marja W. Kanning Maurits Burgering Leo Mulleners Arjen Sein Piet Buwalda 《Food Hydrocolloids》2009
Amylomaltase-treated starch (ATS) is an excellent creaminess enhancer in yoghurt. Small amounts of ATS raised the creaminess perception of low-fat yoghurt (1.5%) to that of full-fat yoghurt (5%). In this way, a reduction in fat-related energy value could be achieved from 45 to 21.5 kcal/100 g product. The functionality of ATS in set yoghurt resulted from discrete domains of ATS that resemble the microstructural behaviour of fat particles. The microstructure of the yoghurt is dominated by the protein and the ATS domains are enclosed in or bound to this protein network. The perceived creaminess resulted from in-mouth melting of these ATS domains due to a combined effect of their physical melting and hydrolysis by amylase present in the saliva. 相似文献
2.
3.
Michael Riis Hansen Andreas Blennow Imad Farhat Lars Nrgaard Sven Pedersen Sren B. Engelsen 《Food Hydrocolloids》2009,23(8):2038-2048
With the aim of generating gelatin-like starch gel functionality, starches extracted from normal potato, high amylose potato, maize, waxy maize, wheat and pea and oxidized potato starch were modified with amylomaltase (AM) (4-α-glucanotransferase; E.C. 2.4.1.25) from Thermus thermophilus. Gel characteristics after storage for 1 and 10 days at 20 °C of 12.0% gels were assessed by monitoring proton relaxation for the resulting 51 enzyme-modified starches and two gelatins using low-field 1H nuclear magnetic resonance (LF NMR) relaxometry. Discrete and distributed exponential analysis of the Carr–Purcell–Meiboom–Gill (CPMG) LF NMR relaxation data revealed that the pastes and gels contained one water component and that the spin–spin relaxation time constants (T2) and distributions differed with respect to starch type and enzyme modification. Typically, AM modification resulted in starches with decreased T2 relaxation time and a more narrow T2 distribution indicating a more homogeneous water population. In contrast, treatment with a branching enzyme (BE) (EC 2.4.1.18) combined with AM increased T2 relaxation time and a broadened T2 distribution. As evaluated by the principal component analysis (PCA), long chains of amylopectin generated hard gels and decreased T2 relaxation time at both day 1 and day 10. Especially at day 10, T2 relaxation time could be predicted from the amylopectin chain length (CL) distribution. Reconstructed amylopectin CL distribution required to emulate gelatin LF NMR data suggest the importance of combined fractions of long (DP 60–80) and short (DP 10–25) amylopectin chains. 相似文献
4.
Gel texture and chain structure of amylomaltase-modified starches compared to gelatin 总被引:2,自引:1,他引:1
Michael Riis Hansen Andreas Blennow Sven Pedersen Lars Nrgaard Sren B. Engelsen 《Food Hydrocolloids》2008,22(8):1551-1566
Amylomaltase (AM) (4-α-d-glucanotransferase; E.C. 2.4.1.25) from Thermus thermophilus was used to modify starches from various botanical sources including potato, high amylose potato (HAP), maize, waxy maize, wheat and pea, as well as a chemical oxidized potato starch (Gelamyl 120). Amylopectin chain length distribution, textural properties of gels and molecular weight of 51 enzyme and 7 non-enzyme-modified starches (parent samples) were analyzed. Textural data were compared with the textural properties of gelatin gels. Modifying starch with AM caused broadening of the amylopectin chain length distribution, creating a unimodal distribution. The increase in longer chains was supposedly a combined effect of amylose to amylopectin chain transfer and transfer of cluster units within the amylopectin molecules.Exploratory principal component analysis (PCA) data analysis revealed that the data were composed of two components explaining 94.2% of the total variation. Parent starches formed a cluster separated from that of the AM-modified starches.Extended AM treatments reduced the apparent molecular weight and the gel texture without changing the amylopectin chain length distribution. However, the gel texture was typically increased as compared to the parent starch. AM-modified HAP gels were about twice as hard as gelatin gels at identical concentration, whereas gels of pea starch were comparable to gelatin gels. Modifying Gelamyl 120 and waxy maize with AM did not change the textural properties. Branching enzyme (BE) (1,4-α-d-glucan branching enzyme; EC 2.4.1.18) from Rhodothermus obamensis was used in just one modification and in combination with AM. The combined AM/BE modification of pea starch resulted in starches with shorter amylopectin chains and pastes unable to form gel network even at concentration as high as 12.0% (w/w). The PCA model of all gel texture data gave suggestive evidence for starch structural features being important for generating a gelatin-like texture. 相似文献
1