教学课程资源库 更多>>

关键词： Emulsion   Mayonnaise   Physicochemical properties   Vegan  

摘要： The food industry has developed a vegan dressing-type mayonnaise due to new consumer demands. The aim of this study was to compare three commercial mayonnaise types with a vegan dressing, measuring their physicochemical properties. Four dressing samples were analyzed: vegan, homemade recipe, creamy, and light. The following properties were measured: water activity, color, droplet size, rheological properties, structural analysis, and oxidative stability. A high color difference was observed between vegan and the other samples due to the presence of chickpea protein. The size and distribution of droplets of the vegan sample were greater than the others. The rheological properties indicated that all samples are non-Newtonian pseudoplastic fluids. The FT-IR results indicated that the highest peak for vegan corresponded to its content in mono-unsaturated fat. Therefore, it showed the lowest oxidative stability. In conclusion, the mayonaise formulations were affected by physicochemical properties such as the content and composition of the oil, thickener and protein contents, along with processing technology.

关键词： Starch  

摘要： Microwave processing has attracted much attention in the field of cereal processing due to its positive effect on improving the nutritional quality of cereals and prolonging the shelf life of cereal food. Microwave (MW) treatment (600 W, 6 min) was studied to evaluate its effect on the physicochemical properties and in vitro digestibility of three kinds of sorghum (Sorghum bicolor [L.] Moench) starch, including Longmiliang No. 1 (LML1), Longza No. 13 (LZ13), and Hongnuo (HN). After microwave treatment, the contents of insoluble dietary fiber, soluble dietary fiber and total dietary fiber of the three kinds of sorghum were significantly increased by 3.72-7.45 g/100 g, 0.33-0.64 g/100 g, and 4.36-7.78 g/100 g, respectively. Microwave treatment also resulted in sorghum starch granules with rough surfaces, an increase in pasting temperature and pasting time, and a decrease in pasting viscosity and transition enthalpy (p < .05). However, Fourier transform near infrared spectroscopy showed that microwaves did not change the chemical groups of sorghum starch. Additionally, after microwave treatment, the in vitro digestibility of sorghum starch was significantly reduced by 3.21-6.61%, the rapidly digestible starch content decreased by 5.88-9.24%, the slowly digestible starch and resistant starch contents increased by 4.63-6.65% and 1.03%-2.41%, and the hydrolysis index (HI) and glycemic index (GI) decreased by 4.98-5.74% and 2.73-3.15%, respectively. These results indicate that microwave treatment is an effective method for decreasing the in vitro digestibility and improving the physicochemical properties of starch. Practical applications Sorghum, as an important raw material in the food industry, plays an irreplaceable role in the development of cereal food. Additionally, microwaves have been used as a novel approach for improving the edible quality and functional characteristics of cereals. A comparative study of the microstructure, pasting properties, thermal properties,

关键词： Portulaca oleracea   Omega-3   Viscosity   Yogurt enrichment   Antioxidant activity   Purslane extract  

摘要： Purslane (Portulaca oleracea L.), belongs to Portulacacae family, and it probably has the highest alpha-linolenic acid content (omega-3) among all green leafy herbs. Therefore, it can be used as a healthy additive for food enrichment due to its beneficial effects for prevention of certain diseases. This study explored the effect of adding purslane extract to plain Yogurt at five levels (0, 0.5, 1, 1.5 and 2%) on some physicochemical properties (pH, titratable acidity, syneresis, viscosity and antioxidant properties) and sensory characteristics (taste, color, odor, texture and overall acceptance). The enriched yogurt was examined for a period of 21 days at 4 degrees C. Physicochemical and sensory properties were investigated at 7-day intervals. The results of statistical analysis showed that the treatment and storage time had a significant effect on physicochemical and sensory properties (p < 0.05). It was also shown that the sample contained 2% extract had lower acidity than other samples and the storage time had a significant effect on this parameter. Besides, the addition of extracts at all levels reduced the syneresis, so that the lowest amount of syneresis was found in the sample contained 1.5% extract. Furthermore, increasing the ratio of the extract in the samples, increased viscosity significantly. Antioxidant activity of the samples containing extracts was significantly higher than yogurt without extract. So, that the highest antioxidant activity was found in the sample contained 2% extract on day zero. Over time, antioxidant activity decreased significantly (p < 0.05). An analysis of sensory characteristics also showed that total acceptance of the samples decreased over time. The samples enriched with 2% purslane extract were considered as the best formulation for enriching yogurt. Besides, purslane extract can be added as good source functional compounds for the enrichment of yogurt.

关键词： Chlorella vulgaris   Arthrospira platensis   Dunaliella salina   Oil-in-water emulsions   Rheology   Mechanical properties  

摘要： Reducing the fat content in emulsions can give additional nutritional health benefits. Hence, developing low-fat oil-in-water emulsions, fortified with healthy microalgae providing advantageous properties, is an interesting topic. In this study, the addition ofArthrospira platensis(Spirulina),Chlorella vulgaris(Chlorella), andDunaliella salina(Dunaliella) microalgae biomass on the physicochemical properties of low-fat oil-in-water emulsion formulations were evaluated. The rheological properties of food emulsions were measured in terms of the viscoelastic, flow behaviour, and textural properties, with all properties studied during 60 days. pH values of all the emulsions ranged between 3.0 and 3.7 and agreed to the Codex Alimentarius Commission. Moreover, their rheological behaviour may be classified as weak gel-like, a distinguishing characteristic of low-fat emulsion products. Substantial differences in rheological properties were observed between the fortified microalgae emulsions over the storage time (60 days). However, incorporating Spirulina or Dunaliella gave emulsions with stable texture, viscoelastic, and rheological properties. The prepared emulsions displayed good colour stability for Chlorella and Dunaliella. Overall, the fortified microalgae low-fat emulsions are expected to provide a blueprint for the design of low-fat mayonnaise-like food emulsions.

关键词： Sorghum   Sprouting   Physico-chemical changes   Macronutrients  

摘要： Sorghum is a cereal with significant genetic erraticism. Germination and fermentation are the traditional processing techniques used to enhance its nutritional efficiency and digestibility. Germinated whole grains contain higher levels of essential amino acids responsible for protein production in the human body. Sprouting partially digests the components of starch and protein, decreases anti-nutritional factors, increases the supply of food materials with minerals and vitamins. Germination also provides desirable flavor and taste. This review sheds a light on the process of germination, physio-chemical changes during sorghum sprouting, the effect of sprouting on macronutrients, the effect of sprouting on anti-nutritional factors, the effect of sprouting on bioactive compounds, along with health benefits. It also discusses the production scenario of sorghum and the consumption scenario of sorghum.

关键词： gel characteristics   myofibrillar protein   physicochemical properties   protein oxidation   rutin  

摘要： The effects of rutin (6, 30, and 150 mu mol/g(pro)) on the physicochemical, structural properties and gel characteristics of myofibrillar protein (MP) under oxidative stress were investigated. The addition of rutin significantly promoted the formation of oxidized MP carbonyl derivatives and dimer tyrosine, but it cannot prevent the loss of sulfhydryl groups (-SH). With increasing rutin concentration, the hydrophobic area was gradually shielded and rutin acted as a quencher to reduce the fluorescence intensity of oxidized MP. Under the oxidative stress, rutin increased the particle size and aggravated the cleavage of protein molecules. SDS-polyacrylamide gel electrophoresis revealed that rutin further aggravated oxidized MP degradation and cross-linked form polymer which cross-linked with protein to the maximum extent at 150 mu mol/g(pro) rutin content. Moderate cross-linking between protein and rutin could improve the gel strength and water holding capacity (WHC) of oxidized MP gel. For rutin concentrations of 6 and 30 mu mol/g(pro), the gels had denser network structures, as observed by scanning electron microscopy. Practical applications Polyphenols of the type and dosage can change the properties of the product itself and optimize the quality of product processing. Certain polyphenols may promote the oxidation process of protein-rich products, but this does not affect the improvement of product quality. The application of natural polyphenols is the promising business direction in the development of Coregonus peled industry.

关键词： Ovotransferrin   Structure   Physicochemical properties   Controlled assembly   Potential applications  

摘要： Background: Ovotransferrin, a native protein with abundant nutritional value and various functionalities, can be applied in numerous food systems. As the second most ample protein in chicken egg white, the physicochemical properties of ovotransferrin influence the performance of egg white in food processing. As a member of transferrin family, ovotransferrin shares many similar features with lactoferrin and thus can be an ideal candidate to make up for the shortage of lactoferrin. Scope and approach: On the basis of ovotransferrin structure, this overview systematically summarizes information on physicochemical properties and controlled assembly of ovotransferrin. Furthermore, the knowledge on potential applications of ovotransferrin in food industry is also reviewed and discussed in detail. Key findings and conclusions: Ovotransferrin is a native protein with ability of iron binding and releasing. A variety of processing techniques as well as interaction with other food ingredients can significantly affect the physicochemical properties of ovotransferrin, and variations on physicochemical properties of ovotransferrin are generally associated with structural changes. Assembly of ovotransferrin with itself or other biopolymers can create various particles with many characteristics different from native ovotransferrin, and assembled particles have exhibited excellent application potential in construction of delivery systems including emulsions and hydrogels. Moreover, ovotransferrin also exhibits tremendous application potential as natural food preservative and functional food ingredient beneficial to human health.

关键词： Dairy waste   Seasonality   Climate change   Dairy waste treatment   Microbial risk  

摘要： Background: The dairy industry is one of the most polluting sectors globally, producing waste identified by the high content of biological and chemical oxygen demand, organic and inorganic matter. The continuous disposal of dairy waste into the environment negatively impacts ecosystems. Seasonality has been shown to affect the physicochemical composition of milk and, consequently, dairy waste. However, the impact of climate change on the dairy sector remains unexplored. Therefore, it is important to understand its impact on dairy waste in relation to environmental safety and the increased risks due to microbial multiplication. Scope and Approach: This review summarises the available data and outlines the characteristics of dairy waste and current waste management strategies. The effect of seasonality on dairy waste, its microbial population and waste management strategies have been elaborated. Finally, the effect of the seasonality of dairy waste has been used as an estimator to predict the impact of climate change. This review aims to provide the latest source of information on the impact of climate change on dairy waste. Key findings and conclusions: Real-time monitoring of environmental changes must be taken into account to determine their environmental impact on dairy waste physicochemical and microbial properties. Seasonal variations provide key insights into the impact of climate change on dairy waste. Further analysis is required to assess microbial behavior under environmental stress in dairy waste and elucidate adaptive mechanisms used by microbes to mitigate stress. New waste management decision tools and legislation will be critical to a sustainable dairy industry resilient to climate change.

关键词： Sorghum   Deep frying   Gluten free chips   Glycemic index   Antioxidant  

摘要： In this study, deep fried gluten free chips were manufactured using sorghum flour at different concentrations (5, 20, 35 and 50 g/100 g) and in vitro glycemic index, total antioxidant capacity and some physicochemical characteristics (dry matter, ash, oil, protein and color) and overall acceptability of the samples were investigated. Protein, oil and total dietary fiber levels of the samples ranged between 5.39-8.28, 23.58-29.10 and 5.59-6.60 g/100 g, respectively and increase in sorghum flour level resulted in an increase in these studied quality parameters of the chips samples. Ferric reducing antioxidant activity and DPPH radical scavenging performance were affected positively by the addition of sorghum flour. Total starch hydrolysis index and estimated glycemic index values were affected by the sorghum flour addition negatively due to the increased total dietary fiber content of the chips samples. All chips samples enriched with sorghum flour showed similar overall acceptability and increased sorghum concentration decreased the preference scores slightly. All these results could be considered for the manufacturing of the gluten free deep fried sorghum based chips samples.

关键词： coal flotation   flotation reagents   physicochemical analysis   salt solution   frothing   flotational froth   adsorption  

摘要： The action of inorganic reagents in coal flotation is analyzed, with a view to improving enrichment. Sulfates of calcium, magnesium, and iron most likely act by diminishing the hydration of coal particles as a result of the surface adsorption of cations. The positive influence of a natural salt solution consisting primarily of NaCl on coal flotation is analyzed: increased frothing in the presence of NaCl electrolyte is due to change in the physicochemical properties of the adsorbed layers, with the formation of heteropolar reagents at the liquid-air interface.