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111.
Wang JL Ruan H Zhang HF Zhang Q Zhang HB He GQ Shen SR 《Journal of food science》2007,72(9):C452-C456
ABSTRACT: An extreme thermostable and acidic tolerable β-glucanase was isolated and characterized from aerobic fungi Trichoderma koningii ZJU-T. The optimal reaction temperature and pH for the β-glucanase were 100 °C and pH 2.0, respectively. The β-glucanase showed increased stability at higher temperatures and lower pH values when compared to other β-glucanases. The optimum conditions for the β-glucanase stability were found to be pH 4.0 and 80 °C. Even subjected to 100 °C for 3 h, β-glucanase activity did not show significant reduction. Moreover, K+ significantly enhanced β-glucanase activity at the concentration of 1 mM, while EDTA and other metal ions such as Mg2+ , Mn2+ , Zn2+ , Ca2+ , Fe2+ , Pb2+ , and Fe3+ inhibited β-glucanase activity. Denaturants, including sodium dodecyl sulfate (SDS) and mercaptoethanol, also inhibited β-glucanase activity at a concentration of 5%. However, in the presence of 7 M urea, residual activity of the β-glucanase still remained 14.5%. 相似文献
112.
ABSTRACT: This study deals with the impact of food structure and texture on aroma release. This was done with cornstarch dispersions with constant concentrations in starch but differing in their structures. The structure parameters of the cornstarch dispersions were varied by changing the shearing conditions during the pasting process. Linalool and isoamyl acetate were chosen as reference aroma compounds. Linalool is known to form complexes with amylose while isoamyl acetate does not. The release of aroma compounds from starch dispersions under stirring was studied at 2 temperatures by discrete sampling of the headspace. Aroma release curves were modeled and the kinetic and thermodynamic parameters were extracted. The release of linalool seemed to be governed mainly by the interactions (complexation) with starch. In contrast, the interactions between starch and isoamyl acetate were feebler, and the release of this aroma compound was governed by the structure of the starch dispersion. The observed interactions were better established at 20 °C than at 32 °C. 相似文献
113.
S. Borchardt C.M. Tippenhauer J.-L. Plenio A. Bartel A.M.L. Madureira R.L.A. Cerri W. Heuwieser 《Journal of dairy science》2021,104(8):9195-9204
The objective of this observational study was to evaluate the association of estrous expression within 40 days in milk (DIM) using a neck-mounted automated activity monitor (Heatime Pro; SCR Engineers Ltd.) with reproductive performance in lactating Holstein cows. A total of 2,077 cows (614 primiparous cows and 1,463 multiparous cows) from 5 commercial dairy farms were included in the statistical analyses. Activity data from the first 7 d after calving were excluded. An estrus event was defined as an activity change index ≥35 for more than 2 h. Cows were classified according to the number of estrus events from d 7 until d 40 postpartum into 3 categories: (1) no estrus event (Estrus0); (2) one estrus event (Estrus1), and (3) 2 or more estrus events (Estrus2). Generalized linear mixed models were used to analyze continuous and categorical data. Shared frailty models were used for time to event data. Overall, 52.7% of cows had no estrus event detected by an automated activity monitor system from d 7 until d 40 postpartum. Herd level prevalence of Estrus0 ranged from 37.5 to 58.4%. Estrous expression from d 7 until d 40 postpartum affected estrous duration and estrous intensity at first artificial insemination (AI). Cows in Estrus0 had the shortest duration (13.2 ± 0.33 h) compared with cows in Estrus1 (13.8 ± 0.36 h) and Estrus2 (14.8 ± 0.41 h). Cows in Estrus2 had a longer estrous duration at first postpartum AI compared with cows in Estrus1. Among Estrus0 cows, 46.2% had an estrus event with high intensity at first postpartum AI. Among cows in Estrus1 and Estrus2, 50.8 and 53.8% had an estrus event with high intensity at first postpartum AI, respectively. There was a significant difference between Estrus2 and Estrus0 and a tendency between Estrus0 and Estrus1. There was no difference between Estrus1 and Estrus2. For Estrus0, Estrus1, and Estrus2 cows, pregnancy per AI was 29.4, 30.9, and 37.8%, respectively. There was a significant difference between Estrus0 and Estrus2 and Estrus1 and Estrus2. There was no difference between Estrus0 and Estrus1. Estrous expression from d 7 until d 40 postpartum affected time to first AI and time to pregnancy. Compared with Estrus0 cows, cows in Estrus1 [hazard risk (HR) = 1.74] and Estrus2 (HR = 1.77) had an increased hazard of being inseminated within 100 DIM. There was no difference between Estrus1 and Estrus2. Median DIM to first AI were 70, 59, and 58 for cows in Estrus0, Estrus1, and Estrus2, respectively. Compared with Estrus0 cows, cows in Estrus1 (HR = 1.28) and Estrus2 (HR = 1.33) had an increased hazard of becoming pregnant within 200 DIM. There was no difference between Estrus1 and Estrus2. Median DIM to pregnancy were 127, 112, and 103 for Estrus0 cows, Estrus1 and Estrus2, respectively. In conclusion, cows with no estrous expression from 7 to 40 DIM had reduced estrous expression at first AI and inferior reproductive performance compared with cows that displayed estrous activity. 相似文献
114.
115.
Mulhern R Fieldman G Hussey T Lévêque JL Pineau P 《International journal of cosmetic science》2003,25(4):199-205
This study sought to investigate whether cosmetics do improve female facial attractiveness, and to determine whether the contribution of different cosmetic products are separable, or whether they function synergistically to enhance female beauty. Ten volunteers were made up by a beautician under five cosmetics conditions: (i) no make-up; (ii) foundation only; (iii) eye make-up only; (iv) lip make-up only; and (v) full facial make-up. Male and female participants were asked to view the 10 sets of five photographs, and rank each set from most attractive to least attractive. As predicted, faces with full make-up were judged more attractive than the same faces with no make-up. Sex differences within the results were also apparent. Women judged eye make-up as contributing most to the attractiveness. Men rated eye make-up and foundation as having a significant impact on the attractiveness of a full facial makeover. Surprisingly, lipstick did not appear to contribute to attractiveness independently. 相似文献
116.
The barley mutant, TR49, selected in Spain for rapid germination, and its parent cultivar Troubadour, were grown in Scotland in 1991 and assessed for a range of grain and malt quality characters. Results suggested that both genotypes had a potential dormancy problem, although TR49 showed a slight but significant improvement over Troubadour. TR49 produced very large grain which did not completely modify during malting, but still showed an advantage over its parent cultivar for all malting parameters assessed. 相似文献