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关键词： Arabic gum   freeze‐   drying   microencapsulation   whey protein isolate   zedo gum  

摘要： The present reports on the microencapsulation of Nigella sativa seed oil (NSO) by freeze-drying via whey protein isolate (WPI), Arabic gum (AG) and Zedo gum (ZG) mixture aimed at producing the optimum sample. The desirability function results showed that the mixture of 27.36% WPI, 32.64% AG without ZG and 40% oil resulted in the production of the optimum sample with minimum Z-average, PDI, and a* and maximum zeta potential, encapsulation efficiency, and b*. The findings demonstrated that lower particle size and particle dispersion index were obtained at higher amounts of AG and WPI with the least a*. The structural and morphological characteristics of the optimum sample were featured by FT-IR and SEM analyses. The C16:0, C18:1 and C18:2 were the main fatty acids in the NSO. Despite the oxidative stability of encapsulated NSO descended after 6 days at 70 degrees C, the peroxide and p-anisidine values were in acceptable range after freeze-drying.

关键词： Legume protein   Amino acid   pH   Surface characteristics   Functional properties  

摘要： Mung bean (MPI), black bean (BPI), adzuki bean (API), rice bean (RPI), black kidney bean (BKPI), speckled kidney bean (SKPI), chickpea (CPI) and cowpea (CPPI) protein isolates were assessed for their surface (charge, hydrophobicity: H-0 and tension) and functional properties (solubility, water/oil holding capacity, WHC/OHC;foaming capacity/stability, FC/FS;emulsifying activity/stability indices, EAI/ESI and least gelling capacity, LGC) at pH 3.0, 5.0, 7.0 and 9.0, using soybean (SPI) and pea (PPI) protein isolates as controls. Physicochemical properties of these proteins, e.g., amino acid composition and colour (L*, a* & b*, WI: whiteness index), were also characterized. API, RPI, BKPI, SKPI and CCPI exhibited a better amino acid profile and protein digestibility than other isolates. BKPI (27.01) and SKPI (20.48) showed higher WI, while CPI (-21.92) was the lowest. For all isolates, H-0 was the highest at pH 3.0, followed by pH 7.0 and 9.0, while surface tension was the highest at pH 5.0, followed by pH 3.0. Compared to other proteins, BKPI and SKPI showed lower solubility, but were more effective to reduce surface tension. Most of the traditional legume proteins had similar EAI. CCPI showed better WHC/OHC and API, RPI, BKPI and SKPI displayed excellent FC/FS. Interestingly, LGCs of MPI (8%), BKPI (4%), SKPI (4%) and CCPI (6%) at pH 3.0 were significantly lower than other isolates (12%). Overall, BKPI and SKPI have good nutritional profiles and also possess excellent functionalities (except for WHC/OHC), which are very promising as new alternative legume proteins to SPI and PPI.

关键词： Climacteric fruit   colour   peel   plantain   respiration   ripening   soluble solids   starch  

摘要： The physicochemical and physiological attributes of three contrasting commercial varieties of Musaceae, Dominico Harton (plantain), Guineo (cooking banana) and Gros Michel (dessert banana), were evaluated and statistically analysed during post-harvest ripening. Quality attributes differed markedly among varieties, both in fresh fruits and during ripening. Variety (V) had a significant effect (P < 0.001) on all attributes except total soluble solids (TSS), carotenes and total chlorophyll. Storage time (ST) had a significant effect on all attributes except colour parameter b* and total carotenes. Starch levels decreased significantly (P < 0.001) during ripening, with nearly complete hydrolysis in Gros Michel, followed by Guineo and Dominico Harton. Discriminant analysis showed that central diameter, TSS of the pulp, colour parameter a* and total starch had the highest weight in the differentiation among varieties. These results point out which parameters may help improve current methods for monitoring ripening of bananas, in particular the commercially important varieties in this study.

关键词： bacaba   Foam-Mat drying   Powder   Antioxidant capacity   Diffusivity  

摘要： This work studied the foam-mat drying (FMD) of bacaba pulp, evaluating the parameters of foam-forming and the effects of thickness layer (5-15 mm) and temperature (50-70 degrees C) during the drying process. The results showed the need for an emulsifier, in addition to the foaming agent, to obtain a low density and stable foam. The powder showed high content of proteins (15.9 +/- 0.6 %), fibers (49.6 +/- 0.4 %), and lipids (35.6 +/- 0.2 %). The combination of the lowest drying temperature and thickness resulted in a final product with good solubility (37.5 +/- 1.2 %) and a high antioxidant capacity (525 +/-;13 mu mol TE g(-1)), which suggests a great potential for use in the development of functional products. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： antimicrobial activity   bacteriocin   food preservative   mode of action   stability  

摘要： Aim Bacteriocins with antimicrobial activity are considered as potential natural bio-preservatives to control the growth of food spoilage bacteria. The aim of this work was to characterize a novel bacteriocin BM1029 discovered fromLactobacillus crustorumMN047 and evaluate its antibacterial mechanism. Methods and Results Bacteriocin BM1029 was purified by cation-exchange chromatography and reversed-phase chromatography. Antibacterial activity assay showed that BM1029 is antagonistic against both Gram-positive and Gram-negative bacteria. Furthermore, it was found that BM1029 showed low haemolysis with high stability to the pretreatment with different temperatures, pH and surfactants. Moreover electron microscopy and flow cytometry suggested that BM1029 inhibit indicator strains by damaging the cell envelope integrity. Cell cycle assay suggested that BM1029 arrested cell cycle in R-phase. Conclusion The novel bacteriocin BM1029 showed high bactericidal activity againstEscherichia coliandStaphylococcus aureusthrough a cell envelope-associated mechanism. Significance and Impact of the Study Application of BM1029 inhibited the growth of indicator strains on beef meat storage at 4 degrees C suggesting that this bacteriocin is promising to be used as a novel preservative in food processing and preservation.

关键词： crosslinking agents   digestibility   physicochemical properties   starch aerogels   vacuum drying  

摘要： In this study, sodium trimetaphosphate, adipic acid, sodium hexametaphosphate, and epichlorohydrin (EPI) are used to investigate the effect of the crosslinking reaction on the physicochemical properties and in vitro digestibility of corn starch aerogel (CSA). Gelatinization destroys the morphology of the corn starch granules, and the crosslinking reaction which is performed in the gelatinization stage considerably alters the structure of the gel. The aerogel prepared by adding 0.5% EPI shows the highest Brunauer-Emmett-Teller surface area among the crosslinked starch aerogels. Corn starch xerogels and aerogels all have porous network structures which may be related to the high amylose structure of corn starch. Gelatinization and crosslinking agents disrupt the short-range molecular order of corn starch, and the crosslinked CSA has relatively lower crystallinity and higher swelling power and solubility than the control. After crosslinking, rapidly digestible starch and resistant starch content of CSAs increase, while slowly digestible starch decreases slightly. Thus, the crosslinked CSA may be used for encapsulation with low digestibility.

关键词： Dioxime   XRD   HSA   MEP   NMR  

摘要： In this study, a novel trans-(1E,2E)-benzil-O,O-dimethylsulfonyl dioxime (BDMDO) monomer was prepared via a one-step dehydrochlorination reaction. BDMDO was characterized by H-1 and C-13 NMR, UV-Vis, and FT-IR spectroscopies, CHN elemental analysis, mass spectrometry, energy-dispersive X-ray spectroscopy, and TGA. According to the X-ray diffraction data, the BDMDO crystal structure was solved as a trans-isomer dioxime. The lattice structure was stabilized by two types of H-bonds and a sufficient number of interesting non-covalent supramolecular interactions such as the C-H center dot center dot center dot H-C bonds. Molecular electrostatic potential measurements and Hirschfeld surface analysis were performed to understand these interaction modes. The cis-trans isomerization in BDMDO as well as the structural, vibrational, NMR, highest occupied molecular orbital/lowest unoccupied molecular orbital bandgap, density of states, and electronic properties were computed by the density functional theory and subsequently compared with available experimental H-1 and C-13 NMR, UV-Vis, and FT-IR spectral data. The thermogravimetric/derivative thermogravimetric behavior of BDMDO was determined experimentally under an open-room atmosphere. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

关键词： Gluten free   Moringa oleifera   Resistant starch   Starch pasting properties  

摘要： Dried powder from Moringa oleifera L. leaves (MOLP) could be considered a promising naturally gluten-free (GF) ingredient to be added in the formulation of GF food products aiming to improve the overall nutritional characteristics. In this work, GF biscuits were formulated by replacing a commercial GF flour mix with 0, 5, 10, and 15 g/100 g of MOLP. Chemical composition, physical and textural characteristics, starch pasting properties, and the in vitro starch digestibility were considered. Adding MOLP increased the amount of protein and total dietary fibre. Even at the lowest MOLP-substitution level, the biscuits had a total dietary fibre content > 6 g/100 g dry matter. Differences in the chemical composition might account for differences in starch properties in terms of pasting behaviour and in vitro digestibility. Using MOLP decreased the in vitro starch hydrolysis index of biscuits, the lowest value (69.3) obtained at the greatest MOLP inclusion level. In addition, an increase in the resistant starch content was reported, passing from 1.1 to 2.7 g/100 g dry matter for GF biscuits containing 0 to 15 g/100 g of MOLP. Colour, spread ratio, and hardness were affected by MOLP inclusion. Biscuits containing 15 g/100 g of MOLP were characterized by the highest hardness value (41.9 N). Substitution level of 10 g/100 g should be considered the threshold level for obtaining a product with similar spread ratio than the control.

关键词： air oxidation   corn starch   crystallinity   digestibility  

摘要： Corn starch is heated (100, 120, 140, and 160 degrees C) under air convective conditions for 4 h. Scanning electron micrograph images show that the treatment produced pores and fractures on the granule surface. Hydroxyl groups of starch molecules are oxidized to carboxyl and carbonyl groups. Increasing heating temperature conditions lead to significant increases in the carboxyl and carbonyl groups contents. Solubility profiles increase while the apparent viscosity of the starch gels (5% w/v) decreases as heating temperature increases. X-ray diffraction shows that the modified starch heated at 160 degrees C has a crystallinity of 6.42% and a short-range ordering of 0.14 as revealed by Fourier-transform infrared ratio 1047/1022, which is significantly lower than the respective values of 24.42% and 0.2 exhibited by native starch. The onset, peak, conclusion gelatinization temperatures, and enthalpy of the modified starches tend to decrease slightly with increasing temperature. The air oxidation treatment affects the digestibility of corn starch, and as temperature increases, the rapidly digestible and slowly digestible starch fractions decrease, while the resistant starch fraction increases significantly. Overall, the results show that heating of corn starch at mild temperature conditions lead to important modifications of the molecular organization and to moderate oxidation of starch chains.

关键词： Dough-like model   Wheat gluten   Rice starch   Physicochemical properties  

摘要： In this study, wheat gluten/rice starch dough-like models were prepared by mixing wheat gluten with rice starch according to different ratios (0:100, 6:94, 8:92, 10:90, 12:88, and 14:86, w/w, based on the dry weight). The physicochemical and structural properties of gluten/rice starch dough-like models were studied. The addition of gluten resulted in higher water absorption, development time, stability time and lower degree of softening. The extensograph, texture profile analysis and rheology results showed that gluten significantly enhanced the viscoelasticity and extensibility of model dough. Moreover, the addition of gluten increased the swelling power and thermal stability, decreased the water solubility and thermodynamic enthalpy. The results of protein aggregation behavior indicated that the addition of gluten promoted the conversion of free sulfhydryl groups to disulfide bonds, which was beneficial to the formation of a uniform and compact protein network. Overall, the addition of gluten significantly improved the quality of gluten/rice starch dough-like model.