共查询到20条相似文献,搜索用时 0 毫秒
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This study was carried out to investigate the possibility of adding nanopowdered eggshell (NPES) into yogurt to improve the functionality of yogurt and the effects of adding NPES on the physicochemical, microbial, and sensory properties of the products during storage. The pH and mean lactic acid bacteria counts of NPES-added (0.15–0.45%, wt/vol) yogurt ranged from 4.31 to 4.66 and from 6.56 × 108 to 8.56 × 108 cfu/mL, respectively, whereas these values ranged from 4.13 to 4.44 and 8.46 × 108 to 1.39 × 109, respectively, for the control samples during storage at 5°C for 16 d, which indicates a prolonged shelf-life with NPES-supplemented yogurt. Color analysis showed that the lightness (L*) and position between red and green (a*) values were not significantly influenced by the addition of NPES. However, the position between yellow and blue (b*) value significantly increased with the addition of the concentration (0.45%, wt/vol) of NPES at d 16 of storage. Sensory evaluation revealed that NPES-added yogurts showed a notably less sourness score and a higher astringency score than the control. An earthy flavor was higher in 0.45% NPES-supplemented yogurt compared with the control. Based on the results obtained from the current study, the concentration (0.15 to 0.30%, wt/vol) of NPES can be used to formulate NPES-supplemented yogurt without any significant adverse effects on the physicochemical, microbial, and sensory properties. 相似文献
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This study was carried out to determine the possibility of adding nanopowdered chitosan (NPC) into cholesterol-reduced yogurt to improve the functionality of yogurt and the effects of adding NPC on the physicochemical, microbial, and sensory properties of the products during storage. The pH values and mean lactic acid bacteria counts of NPC-added (0.3 to ∼0.7%, wt/vol) and cholesterol-reduced yogurt ranged from 4.19 to 4.41 and from 4.75 × 108 to 9.70 × 108 cfu/mL, respectively, when stored at 4°C for 20 d, thereby indicating a possibility of prolonging the shelf life of yogurt. In color, the a* and b* values for cholesterol-reduced yogurt were not significantly influenced by the addition of NPC (0.1 to ∼0.7%, wt/vol); however, the L* values significantly decreased with the addition of the greatest concentration (0.7%, wt/vol) of NPC at 0-d storage. The sensory test revealed that the astringency scores significantly increased at 0-d storage when the greatest concentration (0.7%, wt/vol) of NPC was added into cholesterol-reduced yogurt. Based on the data obtained from the current study, it is concluded that concentrations (0.3 to ∼0.5%, vol/vol) of NPC could be used to produce an NPC-added and cholesterol-reduced yogurt without significantly adverse effects on the physicochemical, microbial, and sensory properties. 相似文献
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Yanyan Huang Shan Zhao Kun Yao Dongmei Liu Xin Peng Juan Huang Yongyao Huang Li Li 《International Journal of Dairy Technology》2020,73(1):168-181
Polysaccharide extracts (0.05 ~ 0.15% w/w) from Lactarius volemus Fr. were used as growth factors and were incorporated into three different probiotic yoghurts. Yoghurts with polysaccharide extracts had a significantly improved water‐retention capacity and reduced pH (P < 0.05). Polysaccharide extracts also significantly increased the viable count and essential amino acid content in the probiotic yoghurts (P < 0.05). The best sensory properties were achieved with the addition of 0.10% polysaccharide extracts. Our study suggests that polysaccharide extracts from L. volemus Fr. are a highly efficient growth factor for shortening the fermentation period and improving the quality of probiotic yoghurts. 相似文献
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Sang Yong Eom Chan Bok Chung Young Sil Kim Jong Heon Kim Ki Soo Kim Young Heui Kim Sun Hee Park Yong-Il Hwang Ki Ho Kim 《International journal of cosmetic science》2007,29(2):140-141
In Korea and China, Ulmus davidiana var. japonica has been used as a traditional oriental medicine for the treatment of difficulty in urination, skin inflammation, etc. In order to investigate the potential of a polysaccharide extract from Ulmus davidiana var. japonica as a cosmetic ingredient, we measured its moisturizing effect, photo‐induced cytotoxicity, and anti‐inflammatory effect. After hydrolysis, HPLC experiments showed that the composition of the polysaccharide extract was mainly rhamnose, galactose, and glucose. The molecular weight of the obtained Ulmus davidiana root extract was 20 000. The intrinsic viscosity was 90 dL/g. In a moisturizing test conducted through the measurement of water loss in a desiccator and of moisture content with a Corneometer CM820, Ulmus davidiana root extract showed almost the same moisturizing effect as hyaluronic acid. In an assay for inhibition of the H2O2‐activated release of PGE2, IL‐6, and IL‐8 in normal human fibroblast cell lines, Ulmus davidiana root extract showed an inhibitory activity of PGE2 release in a dose‐dependent manner (up to 85.9% at a concentration of 0.1%). The percent inhibition of the release of IL‐6 was in the range of 45.6–64.5% (H2O2 was used as the positive control). Moreover, the release of IL‐8 was completely inhibited in the entire concentration range (>0.0025%). In a test of recovery from photo‐induced damage after UVA irradiation (3 J/cm2), the cell recovery of human fibroblasts increased to levels two times higher than that of the positive control, which was UVA‐damaged cells in the absence of Ulmus davidiana root extract (up to 60.2% at 3.0% of Ulmus davidiana root extract). In a photo‐induced cytotoxicity assay in the presence of promethazine as a photosensitizer, Ulmus davidiana root extract showed approximately 48% of the increased cell viability of the control. Therefore, Ulmus davidiana root extract may be useful for the development of a cosmetic ingredient. 相似文献
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Marta M Calvo Antonia Montilla Angel Cobos 《Journal of the science of food and agriculture》1999,79(9):1208-1212
The influence of milk acidification up to pH 6.0 with CO2 on D ‐ and L ‐lactic acid production and lactose consumption by yogurt starter, changes in the pH, and rheological and sensory properties of yogurt were studied. A slight influence of CO2 on lactic acid production during yogurt manufacture was detected. No significant changes in lactic acid concentration were observed during storage, although the final concentration was significantly lower in control than in pH 6.2 and 6.0 acidified samples. A great influence of CO2 on D ‐lactic acid production was not observed. Yogurt manufactured from milk with lower pH values showed lower final pH values after 7 days of storage. The viscosity was similar in all analysed samples. No significant differences in sensory characteristics between unacidified and acidified yogurts were detected. © 1999 Society of Chemical Industry 相似文献
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The strong gelling property of psyllium polysaccharides is closely related to its health benefits and applications, such as use as a binding agent in the landscape industry. However, information about gelling properties of psyllium polysaccharides is very limited. To explore the gel properties of psyllium, the alkaline extracted gel fraction (AEG) of psyllium polysaccharides was studied in this investigation. The rheological and low-temperature electron microscopy methods including cryo-scanning electron microscopy (Cryo-SEM) and freeze-substitution for transmission electron microscopy (TEM) were used to investigate Ca2+ influence on the gel properties of AEG. AEG formed a weak gel with a fibrous appearance. AEG did not have a sharp melting point and exhibited no thermal hysteresis during heating and cooling procedure. The origin of this gelling behaviour was due to the fibrillar gel structure of psyllium polysaccharide. It was found that Ca2+ had a significant influence on the gel properties and microstructure. Elastic modulus G′ of gel increased as Ca2+ concentration increased. Critical strain S at first increased and then decreased as Ca2+ concentration increased. AEG gel became more resistant to temperature change on addition of Ca2+. Psyllium gel changed to aggregated gel with added Ca2+. The strands of gel appeared thicker and the density of the junction zone increased with increasing Ca2+ concentration as revealed by SEM and TEM. The changing bulk gelling properties of psyllium polysaccharide by adding Ca2+ was attributed to the change in gel structure. 相似文献
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A Saravana Kumaar A Senthilkumar T Sornakumar S.S Saravanakumar V.P Arthanariesewaran 《Journal of Natural Fibers》2019,16(2):175-184
This article presents the characteristics of Carica papaya fibers (CPFs) extracted from the bark of the perennial papaya plant. Detailed chemical compositions of CPFs such as cellulose, lignin, ash, moisture, and wax contents were established and determined by using standard methods. Further, chemical groups, crystalline structure, surface roughness, and thermal stability of CPFs were examined using Fourier transform infrared analysis, X-ray diffraction, atomic force microscope, and thermogravimetric analysis, respectively. The physico-chemical properties of CPFs, crystallinity index (56.34%), cellulose content (38.71 wt. %), hemicellulose (11.8%), and density (943 kg/m3) were compared to those properties of other natural fibers. The results suggest that the biodegradable CPFs can be used as a potential reinforcemnet in the polymer matrix composite structure. 相似文献
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乳酸菌发酵能够产生淀粉酶。为考察含有活性乳酸菌的酸奶对淀粉黏弾特性的影响,本文以玉米淀粉为原料,分别加入1%(v/v)的蒙牛酸奶、完达山酸奶、伊利酸奶,并在37℃保温1小时;用流变仪研究发酵后玉米淀粉的流变学性质。实验结果表明:剪切流变曲线服从Herschel-Bulkley模型 (R>0.90)。屈服应力τ0、粘度系数k增加,流动指数n减小(n<1),显示发酵后的玉米淀粉仍然是非牛顿、屈服假塑性流体。震荡流变曲线显示添加酸奶的样品组的贮能模量G''与损耗模量G''均大于空白组、且均随着剪切频率的增大而增大。本项研究首次发现经乳酸菌发酵的玉米淀粉,具有更高的黏弹特性。 相似文献
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探讨了不同发酵温度下酸乳的表观黏度与剪切速率及时间之间的关系,并对酸乳持水力、胶体脱水收缩作用敏感性等流变学特性进行了研究。结果表明,不同发酵温度酸乳的黏度随剪切时间的延长而变小,并最终趋于平缓,都形成了触变环。表明是触变体系,酸乳触变环面积(37℃>40℃>43℃)与黏度具有很好的相关性。酸乳的表观黏度随剪切时间的变化曲线符合幂函数y=kx-n的变化规律。37℃发酵酸乳的持水力达到最高值,分别较40℃和43℃发酵酸乳的高出18%和8%,而胶体脱水收缩作用敏感性值最小,比40℃和43℃发酵酸乳的分别低13%和5%。表明低温发酵酸乳的黏度大,乳清析出少,稳定性好。 相似文献
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Anil Kumar Siroha 《International Journal of Food Properties》2018,21(1):1371-1385
The effect of epichlorohydrin (0.5%) as a cross-linking agent on physicochemical, rheological, morphological, and in vitro digestion properties of pearl millet starches from different cultivars was studied. Degree of cross-linking (DC) ranged between 40.61% and 89.75%, lower values of DC were observed for cv.HC-10 and cv.HHB-67 whereas higher values were observed for cv.HHB-223 and cv.GHB-732. Cross-linked starch from cv.GHB-732 showed the lowest amylose content, swelling power, and solubility as compared to other cultivars. Rheological properties of starches during heating showed their elastic behaviour. G′ value was much higher than the G′′ value at all frequency values for starch pastes. Plots of shear stress (σ) versus shear rate (γ?) data for cross-linked starch pastes were fitted to Herschel-Bulkley model and yield stress (σo), flow behaviour index (n), and consistency index (K) were evaluated. Scanning electron micrographs (SEM) investigations revealed that cross-linked starch granules had slightly rough surfaceand grooves with slight fragmentations. Readily digestible starch (RDS) of cross-linked starches varied from 46.1% to 50.6%, cv.GHB-732 had the lowest value. Slowly digestible starch (SDS) and resistant starch (RS) content of cross-linked starches ranged from 34.5% to 36.4% and 13.6% to 19.4%, respectively. cv.HC-10 had the highest value for SDS content while the highest RS content was observed for cv.GHB-732. In comparison to native starches, cross-linked modification decreased SDS and RDS content whereas RS content was increased. 相似文献