Wilczynska, AleksandraKukulowicz, AnitaLewandowska, Anna
4页
查看更多>>摘要：Consumption of edible flowers in Poland, just like all over the world, is increasing due in part to their nutritional benefits. Due to edible flowers being usually eaten fresh or minimally processed, the consumption of flowers can pose a microbiological hazard. The aim of this study was to determine the microbial quality of selected edible flowers produced in Poland. In particular, the presence of pathogenic microorganisms (Escherichia coli, Salmo-nella sp. and Staphylococcus aureus) and moulds, as well as yeasts were determined. The results demonstrated that no Salmonella sp. were present in investigated flowers. E. coli was found only in nasturtium flowers. All flower samples contained Staphylococcus aureus at (>) 3 log CFU g(-1) and the total yeast and mould loads were less than 6 log CFU g(-1). The method of harvesting did not affect the microbial contamination.
查看更多>>摘要：The effects of high-pressure processing (HPP) at different levels (0.1-600 MPa) and pressure coupled with twostage heat treatment on the gel properties and water migration of Nemipterus virgatus surimi were studied. The gel prepared by HPP at 100 or 200 MPa for 15 min, followed by a two-stage heating, namely 100 P H and 200 P H respectively, showed the improved the gel strength, water-holding capacity (WHC) and whiteness (P < 0.05). The gel strength of the 100 P H sample was higher than that of the two-stage heated gel sample and the optimal HPP sample (300 MPa/15 min), increased by 124.14% and 131.43%, respectively. Under 100 MPa, HPP induced increased beta-sheet and the exposure of reactive sulfhydryl groups, while the endogenous transglutaminase (TGase) of surimi maintained high activity. The subsequent heat treatment promoted the cross-linking induced by the endogenous TGase, the formation of protein-protein disulfide bonds and hydrophobic-hydrophobic interactions, forming a dense three-dimensional network. In addition, the enhanced interaction of protein-water restricted the migration of immobile water to free water. These ultimately rendered better gel properties. However, excessively high levels of pressures (300-600 MPa) coupled with heat treatment resulted in disordered gel structure, causing less immobile water with higher free water, leading to weak gels.
查看更多>>摘要：Surplus bread is a major bakery side stream that should be strictly kept within the human food chain to reduce waste and ensure resource efficiency in baking processes. Optimally, surplus bread should be recycled as a dough ingredient, however, this is known to be detrimental to the volume and texture of bread. The purpose of this study was to investigate how gelatinized starch in surplus bread, untreated or enzymatically hydrolyzed, affects dough development, bread volume and textural attributes. Starch was hydrolyzed to various degrees using commercial alpha-amylase and amyloglucosidase. Bread hydrolysates containing different carbohydrate profiles (untreated, 75%, 57%, and 26% starch remaining) were evaluated as dough ingredients. More complete starch hydrolysis resulted in better dough visco-elastic properties and higher dough level, and reduced dough water absorption by 13%. Nonetheless, breads containing hydrolysate with high-malto-oligosaccharides had the lowest intrinsic hardness and similar volume yield when compared to control bread. Furthermore, compared to untreated slurry, the hydrolysate with high-malto-oligosaccharides, reduced crumb hardness by 28% and staling rate by 42%, and increased specific volume by 8%. The present findings show that enzymatic hydrolysis dramatically transforms the impact of gelatinized starch. Thus, by selecting correct bioprocessing approaches, bread recycling performance may be significantly improved.
查看更多>>摘要：The nutritional profile of human milk varies significantly during storage, and the impact of storage conditions on phospholipid (PL) composition and fat globule structure is not well studied. This study aimed to investigate the changes in human milk PL composition and human milk fat globule (HMFG) structure during long-term storage, at 4 degrees C,-20 degrees C and-80 degrees C for 30, 60, 90 and 120 days. The PLs in human milk were quantified using 31P NMR, and the microstructure of HMFG was observed using multi microscopes. After 120 days of storage, the total PLs decreased from 19.1 mu mol/100 mL milk to 4.8 mu mol/100 mL, 8.2 mu mol/100 mL and 10.3 mu mol/100 mL at 4 degrees C,-20 degrees C and-80 degrees C, respectively. Glycerophospholipid showed a higher lipolysis rate than sphingomyelin. PLs on milk fat globule membranes degraded during storage, which caused the release of internal triacylglycerols and the flocculation of fat globules at the broken membrane.
Grzelak-Blaszczyk, KatarzynaGrzegorzewska, MariaKlewicki, Robert
7页
查看更多>>摘要：The aim of the study was to examine mass transport, retention, and migration of polyphenols of selected onion varieties during osmotic dehydration. The varieties Alonso F1, Hystore F1, Hysky F1 and Red Lady F1 were treated with 40 degrees Bx sucrose solution containing NaCl (5 g/100g) at 20 degrees C for 5 h. The greatest increase in the dry substance level occurred in the first hour -from approx. 12-13% to approx. 21-23%. Onions of the Hystore variety lost the most water, and Hysky the least. The sum of polyphenols in the raw material was from 711 mg/ 100g of d.m. (Hysky) up to 1228 mg/100g of d.m. (Hystore); it consisted of quercetin-3,4'-O-diglucoside, quercetin-4'-O-glucoside, quercetin-3-O-glucoside, quercetin-3-O-(6 ''-acetyl-glucoside) and quercetin. The retention of polyphenols after 1 h of dehydration was 73-85%, from 5 to 19% of these compounds went into the solution. After a different time, less than 10% polyphenols were degraded in Red Lady and Alonso varieties, and in Hystore and Hysky up to approx. 30%. The main polyphenols, quercetin-4'-O-glucoside and quercetin-3,4'-O- diglucoside, showed similar stability during dehydration.
查看更多>>摘要：The oxidation process of soybean oil enriching with the phenolic extract of Camellia oleifera seed cake (PE), tertiary butylhydroquinone (TBHQ) and tea polyphenol palmitate (TPP) was evaluated under frying condition with H-1 nuclear magnetic resonance (NMR). The results showed that PE and TBHQ could inhibit the degradation of unsaturated acyl groups and reduce the generation rate and concentration of oxidative compounds, with PE having better performance. The hydroperoxides and their associated (Z,E)-and (E,E)-conjugated dienes of soybean oil were only detected at 220 min, and soybean oil with PE had the lower intensity of H-1 NMR signals. In addition, the nine individual polyphenols significantly reduced during frying, and only three phenolic acids were detected even after 420 min, although their content was extremely low. All results suggested that phenolic extracts could provide an effective alternative to synthetic antioxidants during the frying process.
Cargnin, Mariana AguiarGasparin, Bruna CarlaRosa, Derval dos SantosPaulino, Alexandre Tadeu...
11页
查看更多>>摘要：The aim of this work was to evaluate the performance of lactase encapsulated in pectin-based hydrogels during lactose hydrolysis reactions. Pectin-based hydrogel and pectin-based composite hydrogel containing pine fiber were synthesized by chemical cross-linking. Lactase was encapsulated in both hydrogels by adsorption. Lactose hydrolysis experiments were conducted by immersing encapsulated lactase in standard lactose solutions, varying pH and temperature. The formed glucose concentrations were determined by UV-vis spectrophotometry, using an enzymatic-colorimetric method. The lactase encapsulation, catalytic activity, lactose hydrolysis and lactase release were affected by the drying of the hydrogel (oven or freeze-drying), pH and temperature variation of the aqueous lactose solution and pine fiber content in the polymer network. The encapsulation efficiencies of lyophilized hydrogels containing 0, 5 and 10% of pine fiber were 69.04 +/- 1.19, 69.57 +/- 0.78 and 71.10 +/- 0.35%, respectively. Slightly lower values were found for air-dried hydrogels. The relative catalytic activities of lactase encapsulated in the hydrogels containing 0, 5 and 10% of pine fiber were, respectively, 52.85 +/- 0.97, 56.26 +/- 1.07 and 57.27 +/- 1.18% (w/w) after three successive cycles of lactose hydrolysis in UHT-milk. Overall, pectin based hydrogels are potential solid supports for preserving the lactase activity during lactose hydrolysis reactions.
Farias, Thayane R. B.Alves Filho, Elenilson G.Silva, Lorena M. A.De Brito, Edy S....
10页
查看更多>>摘要：This study evaluated the effects of two cold plasma technologies, glow discharge plasma and dielectric barrier discharge plasma (DBD), on the chemical composition of apple cubes and apple juice analyzed by 1H NMR coupled with chemometrics. The effects of different technologies (glow discharge and DBD) and operating conditions (processing time, gas flowrate, and excitation frequency) were evaluated on the concentration of sugars and organic acids of apple juice and apple cubes. Changes in sugars and organic acids were observed after the application of both plasma technologies. Glow discharge plasma application induced the decrease in sucrose content and the increase in glucose, fructose, and malic acid. Dielectric barrier discharge plasma induced sugar reduction and increased malic acid content. Cold plasma technology depolymerized sucrose into glucose and fructose by cleavage at the ether bond. DBD plasma further induced glucose and fructose consumption, most probably through the phenylpropanoid mechanism. Cold plasma technology could be used to modulate apple products' sensory characteristics, altering both sweetness and sugar-acid ratios.
Barua, SreejaniKhuntia, AnjaliSrivastav, Prem PrakashVilgis, Thomas A....
9页
查看更多>>摘要：Consumption of highly digestible native starch is considered to be detrimental for diabetes and obese patients. To address this issue, starch extracted from elephant foot yam was subjected to the heat moisture treatment (HMT) using various heating sources i.e. hot air oven (HAO), microwave (MW), and autoclave (AL). The research focuses on the key characteristics and relationships between various functionalities and digestion parameters of the starch system, which substantially effects the formulation of the low digestible food products. The First-order kinetic model was employed to understand the digestion kinetics of native and modified elephant foot yam starch (EFYS). The multivariate analysis highlighted the significant effect of amylose and short range molecular order (R-1047/1022) on the formation of resistant starch content. Principal component analysis (PCA) and Pearson's correlation coefficient revealed solubility as the crucial parameter for altering the rapidly digestible starch fractions. Hierarchical cluster analysis (HCA) showed a similar treatment effect of AL and MW, whereas HAO modification had the greatest influence on EFYS. Compared to other treated EFYS, HAO modified EFYS containsthe lowest glycemic index, making it ideal for forming diabetic-friendly food products.
查看更多>>摘要：Dark brown sugar (DBS) is a food material, the safety and quality, as well as prices of which are related to the nature of raw material (sugarcane), the production methods, and processes variables. Considering food fraud and safety, it is worth developing a simple approach to check the authenticity of DBS. Therefore, ultraviolet-visible and three-dimensional fluorescence spectroscopies, the quick and environmentally-friendly analysis methods, as well as mass spectrometry were evaluated for DBS authentication in this study. Principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to the data matrix obtained from these analyses. Results show that three-dimensional fluorescence spectroscopy can be effectively used for DBS authentication, because natural and commercial DBS forms different clusters in PCA and LDA plots. Cross-validation further indicates that the LDA of data obtained from three-dimensional fluorescence spectroscopy is able to discriminate main products of natural and commercial DBS. Notably, mass spectrometry may have the potential to quickly identify added caramel in DBS. This will be helpful for the establishment of a rapid quality control method for brown sugar materials in the food industry, which may reduce fraud of related raw materials and ensure food safety.
NSTL
Elsevier