6,959 research outputs found
Effect of pre-germination time of brown rice on serum cholesterol levels of hypercholesterolaemic rats.
Background: Brown rice is unpolished rice with immeasurable benefits for human health. Brown rice (BR) and pre-germinated brown rice (PGBR) are known to contain various functional compounds such as gamma-oryzanol, dietary fibre and gamma-aminobutyric acid (GABA). In the present study, the experimental diets containing BR and PGBR (24, 48 h pre-germination) were used to investigate the influence of pre-germination time of brown rice on blood cholesterol in Sprague-Dawley male rats.
Result: Hypercholesterolaemia and elevation of LDL-cholesterol were successfully ameliorated by the experimental diets containing BR and PGBR (24 and 48 h pre-germination). As compared to the control sample, the pre-germination time had a significant (P < 0.05) effect on blood cholesterol of Sprague-Dawley male rats. It was also found that the significantly (P < 0.05) better effect on lipid profile of hypercholesterolaemic rats was observed by prolonging the pre-germination time. As compared to non-germinated brown rice, the germinated brown rice showed the higher cardio-protective effect on hypercholesterolaemic Sprague-Dawley male rats.
Conclusion: The present study suggests that the changes of blood cholesterol can be mainly modulated by using the PGBR rather than BR. The prolonging of pre-germination time led to an increase in the bioactive components, thereby providing a more efficient functional diet affecting the high blood cholesterol. This study suggests that PGBR can be used instead of BR and polished rice in the human diet
Teaching Chemistry to Students with Disabilities: A Manual For High Schools, Colleges, and Graduate Programs - Edition 4.1
Ever since it was first published, Teaching Chemistry to Students with Disabilities: A Manual for High Schools, Colleges, and Graduate Programs has served as a vital resource in the chemistry classroom and laboratory to students with disabilities as well as their parents, teachers, guidance counselors, and administrators. The comprehensive 4th edition was last updated in 2001, so the American Chemical Society’s (ACS) Committee on Chemists with Disabilities (CWD) thought it prudent to update such a valuable text at this time. In a changing time of technology, rapid access to information, accessibility tools for individuals with disabilities, and publishing, Edition 4.1 is being published digitally/online as an Open Access text. Having Teaching Chemistry to Students with Disabilities: A Manual for High Schools, Colleges, and Graduate Programs in this format will allow for widespread dissemination and access by maximum numbers of readers at no cost- and will allow the text to remain economically sustainable.https://scholarworks.rit.edu/ritbooks/1001/thumbnail.jp
The effect of bone choice on quantification of mineralization in broiler chickens up to 6 weeks of age
An experiment was conducted to assess the most appropriate bone type for measuring bone mineralization in male broiler chicks up to 42 d. A total of 72 male broilers were raised in 0.64 m2 pens on a litter floor. The study design included 2 dietary treatments (Control and Low) containing differing levels of total phosphorus (7.8 and 4.4 g/kg for Control and Low diets respectively) and calcium (22.7 and 13.1 g/kg for Control and Low diets respectively) with each fed to 6 replicate pens of 6 birds. Each wk, 6 birds per diet were euthanized and leg bones removed to measure ash percentage. Foot, toe, tibia, and femur ash were compared using the mean of both legs from each bird, via t-tests to separate Control and Low diets. At the end of wk 1, diets could not be separated using any of the bone ash measures. From wk 2 to wk 5, both tibia and foot ash differentiated between the Control and Low diets, and tibia continued to show significant differences between the diets into wk 6. Femur ash did not show any dietary differences until wk 3, but then showed significant differences between the diets until wk 6. Toe ash only differentiated between diets at wk 2, and variation both within and between birds was high, particularly with younger birds. These results suggest that bird age has implications when choosing a bone for assessing possible differences in dietary phosphorus and calcium uptake. Femur ash may be more appropriate for showing differences in broilers aged 6 wk and older. Foot ash provides a comparable alternative to tibia ash in birds aged 2 to 5 wk of age, providing a labor- and time-saving alternative
Physicochemical aspects of the higher order structure of gelatin in dilute aqueous solution
The conversion of collagen to gelatin results in a heterogeneous product with a broad molecular weight profile (MWP). Addition of a non-solvent, such as ethanol, to gelatin solutions gradually causes the Florey-Huggins solvent-protein interaction parameter to exceed the critical value for the different molecular weight fractions, causing desolvation of the polymer. When sufficient solvent molecules are removed, the gelatin molecules begin to aggregate, resulting in phase separation, and forming a coacervate. Modification of the net charge of the protein, by adjusting the solution pH to values ranging about the iso-electric point (IEP), influences the degree of interaction between the different molecular weight fractions, and hence the response of the protein to non-solvent.peer-reviewe
Physical properties of yogurt fortified with various commercial whey protein concentrates
The effects of whey protein concentrates on physical and rheological properties of yogurt were studied. Five commercial whey protein concentrates (340 g kg−1 protein nominal) were used to fortify milk to 45 g protein kg−1. Fermentation was performed with two different starters (ropy and non-ropy). Resulting yogurts were compared with a control yogurt enriched with skim milk powder. The water-holding capacity of the yogurt fortified with skim milk powder was 500 g kg−1 and ranged from 600 to 638 g kg−1 when fortified with whey protein concentrates. Significant rheological differences have been noticed between the yogurts fortified with different whey protein concentrates, independent of the starter used. Three whey protein concentrates generated yogurts with a behavior similar to the control. The two others produced yogurt with lower firmness (15 g compared with 17 g), lower Brookfield viscosity (6 Pa s compared with 9 Pa s), lower yield stress (2 Pa compared with 4 Pa), lower complex viscosity (13 Pa s compared with 26 Pa s), and lower apparent viscosity (0.4 Pa s compared with 1 Pa s) than the control, respectively. The yogurts with the lowest firmness and viscosity were produced with concentrates which contained the highest amount of non-protein nitrogen fraction (160 g kg−1 versus 126 g kg−1 of the total nitrogen), and the highest amount of denaturation of the whey protein (262 versus 200 g kg−1 of the total nitrogen)
Near infrared reflectance spectroscopy for the determination of free gossypol in cottonseed meal
Gossypol is a toxic polyphenolic compound produced by the pigment glands of the cotton
plant. The free gossypol content of cottonseed meal (CSM) is commonly determined by the
American Oil Chemists’ Society (AOCS) wet chemistry method. The AOCS method, however,
laboratory-intensive, time-consuming, and therefore, not practical for quick field analyses.
To determine if the free gossypol content of CSM could be predicted by near infrared reflectance
spectroscopy (NIRS), CSM samples were collected from all over the world. All CSM samples
were ground and a portion of each analyzed for free gossypol by the AOCS procedure (reference
data) and by NIRS (reflectance data). Both reflectance and reference data were combined in
calibration. The coefficient of determination (r2) and standard error of prediction (SEP) were
used to assess the calibration accuracy. The r2 was 0.728, and the SEP was 0.034 for the
initial calibration that included samples from all over the world. However, the r2 and SEP
improved to 0.921 and 0.014, respectively, if the calibration was made using CSM samples
only from the United States. These results indicate that a general prediction equation can be
developed to predict the free gossypol content of CSM by NIRS. From a practical standpoint,
NIRS technology provides a method for quickly assessing whether a particular batch of CSM
has a free gossypol content low enough to be suitable for use in poultry diets.This research was supported in part by grant 05-635GA from the Georgian Cotton Commission, Perry, G
Evaluation of strategies for preservation of microalgae Chlorella
[EN] The biomass obtained from microalgae, such as Chlorella, is used to make dietary products, supplements and pharmaceuticals. However, microalgae are produced very far from consumption places. One of the most usual distribution forms is as a dry product, a process that entails high production costs and leads to the loss of certain nutritional properties. Therefore, the aim of this study was to evaluate alternative preservation strategies for microalgae Chlorella other than dehydration and freezing. To that end, sterilization, acidification, and packaging material were analyzed during 2 months of storage under different temperature and light exposure conditions. The results showed that color was modified considerably by sterilization, regardless of light exposure and type of package, whereas citric acid preserved color, especially at low storage temperatures. Furthermore, the study shows that acidification with 3.5% of citric acid and vacuum packaging are the recommended treatment for microalgae, without the need for cold storage.
Practical applicationsStabilization of microalgae Chlorella from production to consumption places could increase the possibilities of commercialization of this product, recently labeled superfood by the UN Food and Agriculture Organization. In order to preserve all their nutritional properties for at least 2 months, acidification with 3.5% of citric acid and vacuum packaging are the recommended treatments, without the need for cold storage.The review of this paper was funded by the Universitat Politècnica de València, SpainCastelló Gómez, ML.; Pariente, G.; Andrés Grau, AM.; Ortolá Ortolá, MD. (2017). Evaluation of strategies for preservation of microalgae Chlorella. Journal of Food Processing and Preservation. 42(2):1-8. doi:10.1111/jfpp.13518S1842
Influence of different cultivation methods on carbohydrate and lipid compositions and digestibility of energy of fruits and vegetables
BACKGROUND
Environmental as well as cultivation factors may greatly influence the chemical composition of plants. The main factors affecting the chemical composition of foodstuff are level and type of fertilizer (conventional and organic cultivation systems), location or soil type, and year of harvest. Organic foods are defined as products that are produced under controlled cultivation conditions characterized by the absence of synthetic fertilisers and very restricted use of pesticides. Very limited information is available regarding the impact of organic cultivation systems on the composition of carbohydrates and fatty acids of fruits and vegetables. The objective was to investigate the influence of organic and conventional cultivation systems on the carbohydrate and fatty acid composition and digestibility of the energy of apple, carrot, kale, pea, potato, andrapeseedoil.
RESULTS
Carbohydrate and lignin values ranged from 584 g kg−1 dry matter in kale to 910 g kg−1 DM in potato, but with significant differences in the proportion of sugars, starch, non-starch polysaccharides, and lignin between the food stuffs. Triacylglycerol was the major lipid class in pea, with 82% of total fatty acids, as opposed to apple, with only 35% of fatty acids of the ether extract. The most important factor influence in the digestibility of energy, and consequently faecal bulking, was the content of dietary fibre.
CONCLUSION
The cultivation system had minor impact on the carbohydrate and lipid composition in the investigated foodstuffs or on the digestibility of energy when assessed in the ratmodel. Faecal bulking was related to dietary fibre in a linear fashion
Emulsifying properties of defatted rice bran concentrates enriched in fiber and proteins
BACKGROUND: Rice bran (RB), a by-product of the rice milling industry, constitutes around 10% of the total weight of rough rice. The interest in the use of RB is centered on its nutritional quality, its low cost, and its extensive worldwide production. As RB is commonly used for oil extraction, the defatted rice bran (DRB) is obtained as a second by-product. The aim of this work was to obtain a defatted rice bran concentrate (DRBC), enriched in protein and fiber, from defatted rice bran flour (DRBF) and to determine its physicochemical and emulsifying properties. RESULTS: To obtain the DRBC, the starch was efficiently hydrolyzed (> 98%) with α-amylase and amyloglucosidase, with a concomitant increase in the proportions of crude protein (from 154.7 to 274.3 g kg−1) and total dietary fiber (from 276.1 to 492.3 g kg−1). Defatted rice bran concentrate exhibited a loss of protein solubility and increased surface hydrophobicity compared with DRBF. Defatted rice-bran concentrate dispersions with and without previous ultrasound treatment were prepared. The sonication led to an increase in the apparent viscosity. Emulsions were prepared with dispersions with and without previous ultrasound treatment and showed high stability in quiescent conditions over 28 days. However, the emulsions prepared with dispersions treated with ultrasound resulted in lower D4,3 values and higher elastic and viscous moduli. CONCLUSION: The rice bran concentrate can be used to obtain stable oil-in-water (O/W) emulsions, including both soluble and insoluble fractions, in acidic and neutral conditions. These innovative findings thus contribute to increasing the added value of this important by-product of the rice-milling industry.Fil: Bonifacino, Carla. Universidad de la República. Facultad de Química; UruguayFil: Franco Fraguas, Eugenia. Universidad de la República. Facultad de Química; UruguayFil: López, Débora Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química y Física. Área Fisicoquímica; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; ArgentinaFil: Wagner, Jorge Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Cabezas, Dario Marcelino. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Panizzolo, Luis Alberto. Universidad de la República. Facultad de Química; UruguayFil: Palazolo, Gonzalo Gastón. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Abirached, Cecilia. Universidad de la República. Facultad de Química; Urugua
Homogenization Pressure and Temperature Affect Protein Partitioning and Oxidative Stability of Emulsions
The oxidative stability of 10 % fish oil-in-water emulsions was investigated for emulsions prepared under different homogenization conditions. Homogenization was conducted at two different pressures (5 or 22.5 MPa), and at two different temperatures (22 and 72 °C). Milk proteins were used as the emulsifier. Hence, emulsions were prepared with either a combination of α-lactalbumin and β-lactoglobulin or with a combination of sodium caseinate and β-lactoglobulin. Results showed that an increase in pressure increased the oxidative stability of emulsions with caseinate and β-lactoglobulin, whereas it decreased the oxidative stability of emulsions with α-lactalbumin and β-lactoglobulin. For both types of emulsions the partitioning of proteins between the interface and the aqueous phase appeared to be important for the oxidative stability. The effect of pre-heating the aqueous phase with the milk proteins prior to homogenization did not have any clear effect on lipid oxidation in either of the two types of emulsions. (Résumé d'auteur
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