查看更多>>摘要：Sage has various biological activity and long tradition of the using in phytopharmaceutical preparations and, recently, in food industry. In this work, the essential oil obtained by hydrodistillation and essential oil and extract obtained by supercritical fluid extraction from sage herbal dust, waste product of filter tea factory, were screened for antimicrobial activity against Escherichia coli in the medium which simulates the conditions in meat and in real system of minced pork. The supercritical fluid extract had much lower effect to the reduction of a number of E. coli in meat simulation medium. The total inhibition of E. coli growth was achieved after 12 h and 24 h with the addition of 0.6 mu l/ml of essential oil obtained by hydrodistilation and supercritical fluid extraction, respectively. The addition of essential oils and supercritical fluid extract of sage herbal dust could be used for the effective control of E. coli growth in minced meat.
查看更多>>摘要：Despite the proven antioxidant and antimicrobial efficiency of nanoemulsions as carriers of essential oils, there is scarce research on their behavior once incorporated into complex food matrices. In the current work, lemongrass or mandarin essential oil (LEO or MEO) nanoemulsions were formulated using three different continuous phases (water, an apple juice model and an apple juice-based beverage). Droplet size,.-potential, colloidal stability as well as the antioxidant and antimicrobial activity were studied. The increase in the complexity of the continuous phase promoted the formation of nanoemulsions with smaller sizes. Consequently, creaming phenomena was prevented in complex systems. Moreover, nanoemulsions formulated using the apple juice-based beverage presented a high antioxidant activity, with values of up to 400 mg Eq. Trolox/mL, probably due to the presence of polyphenols. Nevertheless, nanoemulsions presented slower and lower inactivation kinetics at increasing complexity of the continuous phase, which may be related to the ability of sugars to protect cell damage. This work evidenced that antimicrobial nanoemulsions within complex food matrices leads to higher colloidal stability and antioxidant activity, but lower bactericidal activity than nanoemulsions alone. Hence, it provides valuable information for the design of complex foods with nanoemulsions as delivery systems of functional ingredients.
查看更多>>摘要：The aim of the study was to identify potential antioxidant peptides from cheese made with Lactobacillus helveticus 1.0612. The results demonstrated that the nutrient composition of cheese was not affected by the addition of Lactobacillus helveticus, and Lactobacillus helveticus maintained its viability at 7.64 log CFU/g at the end of ripening. Lactobacillus helveticus can significantly increased the antioxidant activity of cheese during ripening time (P < 0.05), and the antioxidant activity reached maximum at the 5th month of ripening time. The potential antioxidant activity water soluble extracts of cheese were fractioned and purified by ultrafiltration and size exclusion technology. The fraction with the highest antioxidant activity was subjected to Q Exactive Plus-Orbitrap mass spectrometer for the identification of peptides. 15 peptides were identified from the most active fractions, and mainly derived from beta- and alpha(s1)-casein. The size of the identified peptide sequence varied from 6 to 14 amino acid residues, and the molecular weight ranges from 700 to 1300 Da. 10 peptides contained at least one hydrophobic amino acids proline residue. Peptides VLPVPQK and EDVPSER have been reported for their antioxidant activity, DKIHPF for ACE-inhibitory activity. Moreover, several new peptides (EMPFPK, KEMPFPK, SDIPNPIGSENSEK), with potential antioxidant activity, have been identified.
查看更多>>摘要：Turanose was evaluated as an alternative to sugar in a frozen dough system in terms of rheology, tomography, and baking performance. The use of turanose for sugar did not negatively affect the thermo-mechanical parameters of wheat dough including development time and stability. In the case of thermal properties, the gelatinization temperature was lowered by turanose from 68 to 64 degrees C. The dynamic viscoelastic measurements demonstrated that the turanose-incorporated doughs showed more viscous characteristics by showing greater decreases in the storage modulus that could also be related to greater dough extensibility. When the frozen doughs were baked, the turanose-incorporated bread showed a significant increase in its specific loaf volume from 4.23 to 4.41 mL/g. These volume differences could be attributed to the inner structural characteristics (increased total volume of pore space and total porosity) of the breads measured by the tomographic analysis. Furthermore, the positive effects of turanose on the soft texture of frozen dough breads were distinctly observed.
查看更多>>摘要：In the following study, it was evaluated selected properties of potato-based snack pellets and expanded puffs enriched with fresh beetroot pulp in the amount of 2.5-30.0 g/100 g. A single-screw extruder with a plasticizing unit of L/D = 18 was used to produce the pellets with various screw speeds. The final snacks were obtained by frying the pellets in vegetable oil. The chemical composition of ready-to-eat snacks, as well as the total phenolics content and antioxidant activity of puffs were assessed. The physical properties, color and texture profile of pellets and snacks were examined, while the snack microstructure was observed using scanning electron microscopy. The results showed that application of fresh beetroot pulp up to 30.0 g/100 g is possible and allows obtaining satisfactory snack quality. Moreover, the final product had increased protein and soluble fiber content, along with enhanced total phenolics content and antioxidant activity. This varied positively with the increase in beetroot pulp content.
查看更多>>摘要：The primary effluent of Indian dairy industries, cheese whey, and its main component lactose is considered an environmental pollutant due to its high chemical and biological oxygen demand. The model fermentative yeast, Saccharomyces cerevisiae, does not possess the necessary enzyme to utilize lactose in whey. In the present study, metabolic engineering of wild type S. cerevisiae strain with CRISPR Cas9 system was used to construct a cell factory that can flux higher galactose from the concentrated whey medium. The improved utilization of galactose confers fermentative metabolism with improved ethanol production rate. The strain provided a high titer of the ethanol (0.32 +/- 0.007 g/g) with improved galactose flux from concentrated whey at the expense of the biomass, glycerol, and acetic acid. Our present study provides evidence that galactose to ethanol fermentation is a feasible alternative for industrial waste stream treatment in developing countries.
查看更多>>摘要：Dry milling process is developed, which is scalable to industrial capacity and more eco-friendly compared to wet method for separation of germ, perisperm and bran fractions from quinoa as potential functional food ingredients. Peripheral germ is the most important functional component of grain as it stores most of the protein and fat reserve. Fractionation of the grain is performed at different conditioning moisture (viz., 12, 14, 16, 18 & 20%). Medium conditioning moisture (14-16%) has shown optimum balance between yield and quality of the fractions; and has been explored further to develop a novel process specifically targeted for germ separation by making significant changes in the flow diagram of the roller milling process. This developed process enables separation of germ with recovery of 82.57% of protein, 80.04% fat and 81.20% of minerals with respect to germ extracted manually. Bran obtained by the developed novel process shows double the amount of dietary fibre compared to quinoa seed; perisperm having <1% mineral content with brightness in colour portrays purity of the fraction. Isolated fraction of quinoa germ has high content of protein, ash and fat. Separated fractions with higher nutritional value have numerous functional applications in food industry.
How, Muhammad SyahmeerJones, Jim R.Morgenstern, Marco P.Gray-Stuart, Eli...
8页
查看更多>>摘要：A conceptual model was developed to relate oral processing parameters and aroma release of cooked white rice. The conceptual model indicates that aroma release is dependent on the increase of particle surface area, the dilution effect of saliva and the diffusion of aroma from food residues that can be trapped in the buccal-pouches in the mouth. The model was validated against in vivo retro-nasal aroma release data during the consumption of rice flavoured with two aroma compounds (2-nonanone and ethyl propanoate) by five panellists. The oral processing behaviour of each subject was characterised at four different stages during oral processing by measuring bolus particle size, saliva content and the amount of residue particles that could be washed from the mouth after bolus expectoration. The results showed that aroma release for all subjects were dependent on the particle breakdown pathways used in oral processing. Subjects who reduced the rice to smaller particle sizes, higher pasted fraction and higher bolus residues had higher aroma release as expected from the conceptual model. Accounting for the physiological variables of subjects, the physicochemical parameters of aroma compounds and using a larger number of subjects in future studies will improve the model reliability.
查看更多>>摘要：Litchi is one kind of the precious tropical fruits, but it is easily affected by enzymatic browning resulting in great loss to farmers. In the present study, dielectric barrier discharge cold plasma was used to inactivate the litchi peroxidase (POD), one of the enzymes responsible for browning. Results indicated that after 10 min treatment, the residual activity of the POD extracted from pericarp decreased to 47.16%. The effect of cold plasma on POD structure was studied by using horseradish peroxidase (HRP) as a model enzyme. The HRP activity was decreased by about 85% after 180 s of treatment. UV and fluorescence spectral results suggested that the secondary and tertiary structures of HRP were changed through plasma treatment, hydrophobic aromatic amino acids and hemes were exposed and modified. Circular dichroism (CD) spectra indicated that after exposed to plasma for 180 s, the content of alpha-helix in HRP were decreased from 21.41% to 8.53%, and the beta-sheet content raised from 23.29% to 32.11%. The presented study concluded that cold plasma is capable of reducing the activity of litchi POD, which will provide a new thought for prolonging shelf life of easy-browning fruits.
查看更多>>摘要：Glass-forming carbohydrates are widely used to encapsulate volatile flavor substances to avoid excessive flavor release and increase storage stability. The objective of this study was to investigate the effects of the crystallization of lactose on the microstructures of powders, as well as subsequent influences on flavor release from lactose-containing matrices. Mixtures of lactose and whey protein isolate were used to constitute the wall materials in ratios of 0:1, 1:4, 1:1 and 4:1 (w/w). Ethyl acetate (EA) was used as a model core material and microparticles were prepared by freeze-drying. Microparticles with higher lactose contents had lower glass transition temperatures and exhibited increased water adsorption behaviors at various water activities (0.33, 0.54 and 0.75 a(w)). A rapid decrease in flavor retention was found in matrices with high lactose contents, especially during storage at 0.75 a(w). X-ray diffraction and crystallinity analysis proved that the degrees of crystallization of lactose in the encapsulation systems differed, which was induced by differences in water activities. Images of microstructures showed that the formation of crystals caused structural modifications of the powder. Consequently, EA particles were prone to accumulate and migrate to the surface of the powder, which resulted in considerable release of EA flavor.
NSTL
Elsevier