Baptista, Sara L.Romani, AloiaFerreira, SaraRocha, Cristina M. R....
8页
查看更多>>摘要：Tagatose is a rare sugar with increasing commercial interest as sweetener. Biotechnological production of D- tagatose by enzymatic isomerization of D-galactose provides an alternative to chemical processes. In the last years, L-arabinose isomerases (L-AIs) from different origins have been studied to increase the effectiveness of tagatose production. In this work, the L-AI from Bacillus subtilis, previously reported to have unique substrate specificity for L-arabinose, was expressed in Escherichia coli and studied for isomerization of D-galactose to D-tagatose. The recombinant enzyme demonstrated, for the first time, tagatose bioconversion capacity, reaching similar to 59% conversion. Furthermore, a sustainable tagatose production strategy was developed by using Gelidium sesquipedale red seaweed and its undervalued processing residues as source of galactose. L-AI successfully con-verted the galactose-rich hydrolysate, obtained from direct acid hydrolysis of seaweed, to tagatose (50.9% conversion). Additionally, the process combining autohydrolysis of G. sesquipedale and acid hydrolysis of the remaining residue allowed a full integral valorisation of polysaccharides: 13.33 g of agar, an important hydro-colloid, coupled with the production of 5.97 g of tagatose. These results confirmed that seaweed biomass and waste-derived are promising substrates for tagatose production by L-AI, contributing to the advancement of circular economy and to the actual needs of food industry.
Darmawan, Kevion K.Karagiannis, Tom C.Hughes, Jeff G.Small, Darryl M....
9页
查看更多>>摘要：Increasingly, lactic acid bacteria have been encapsulated into food formulations because of their health advantages, including modulation of the gut microflora. However, the molecular mechanism on how these bacteria interact with the encapsulating agent, which is typically composed of milk proteins is not fully comprehended. Accordingly, molecular dynamics simulations were employed to investigate the interaction between the cell wall component of these bacteria, specifically the peptidoglycan layer and a protein complex, comprising apolactoferrin, beta-lactoglobulin, and alpha-lactalbumin at spray drying temperatures (68 and 110 degrees C). The results demonstrate that the peptidoglycan model interacts with the posterior N-lobe of apo-lactoferrin and the three turn alpha-helix of beta-lactoglobulin via van der Waals, electrostatic, and non-polar solvation interactions. Free energy calculations also show higher binding affinity at 110 degrees C than 68 degrees C, indicating that elevated temperatures are essential to facilitate hydrophobic interactions between the peptidoglycan component and the N-lobe of apolactoferrin. Furthermore, the secondary structure and the antibacterial regions in apo-lactoferrin are maintained following thermal simulations. The simulations not only highlight the formation of a stable complex, involving the peptidoglycan component, apo-lactoferrin, beta-lactoglobulin, and alpha-lactalbumin, but also the preservation of the functionalities of apo-lactoferrin, which may provide valuable insights into the development of novel nutraceuticals.
查看更多>>摘要：In this study, the structural, antioxidant, antidiabetic, antiobesity, and antimicrobial properties of two himalayan apple seed varieties (red delicious (RD) and golden delicious (GD) was investigated. The morphological characterization of seed flours revealed starch granules of varying shapes and dimensions with agglomerated protein bodies. XRD shows high crystallinity, while as the FTIR spectroscopy indicates high intensity of bands at 1639 cm-1 and 1528 cm-1 in RD seed flour, which are characteristics of amine I and II. Besides, higher phenolic content (12.30 mgGAE/g) was observed in RD which provided excellent results for antioxidant capacity as measured by DPPH radical scavenging capacity assay (49.2-86.9%), reducing power, and inhibition of lipid peroxidation (38.2-86.3%). Consequently, RD flour exhibited higher alpha-glucosidase (34.5-86.6%) and pancreatic lipase (24.9-72.6%) inhibition. The antimicrobial study revealed that both flour samples inhibit the growth of B. subtilis and S. aureus. This study therefore suggests the possible use of apple seeds in different food formulations.
查看更多>>摘要：This study aimed to assess the robustness of the NIRS models developed following different strategies for the routine prediction of nitrate content in spinach plants using an online FT-NIR spectrophotometer. To achieve this, 516 spinach plants from different cultivars, harvest dates, orchards and seasons, were used. Two strategies were followed to make up the calibration and validation sets; the first included in the calibration set those samples belonging to the 2018 and 2019 harvesting seasons, while the second also included in this set part of the population of the 2020 harvesting season. Modified partial least squares quantitative models were initially developed and externally validated. In view of the results and to obtain significant improvements, a non-linear regression technique (the LOCAL algorithm) was applied. The models developed using the non-linear regression technique and considering the greatest possible variability in the training set (samples belonging to 2018, 2019 and 2020 harvesting seasons) reported the best prediction results (R-p(2) = 0.60; SEP = 758 mg/kg), which enabled to classify the product in the main categories or classes established by the official regulations, according to its commercial destination.
Moller, Anna Cacilievan der Padt, Albertvan der Goot, Atze Jan
3页
查看更多>>摘要：Making use of crops structural break-up during pearling and subsequent fractionation into starch or protein enriched fractions was investigated using stepwise pearling as a method. In first instance, pearling resulted in separation of pea testa and embryonic axis from the cotyledon. Further around 20% of the yellow pea cotyledon was pearled off and collected separately from the inner kernel. All four fractions were finely ground and their composition analysed. Due to the di-cotyledon structure of the pea, solely pearling the outer kernel couldn't be guaranteed. Therefore, the process was repeated by hand-dissection, to ensure only separation of the outer 20% cotyledon. Pearling resulted in size reduction and separation of testa, embryonic axis and the outer and inner part of the cotyledon. Although, no considerable enrichment was achieved in protein or starch content in the pearled fraction of the outer and inner cotyledon, pearling gave the opportunity to obtain the testa fraction, which according to literature is rich in dietary fibre. Moreover, the protein-rich embryonic axis was separated and collected. The testa fraction accounts for 7-8% of the whole pea and contains little protein and starch, which makes it a promising dietary fibre rich ingredient in food application.
Maqbool, HafsaSafeena, Muhammed P.Abubacker, ZynudheenAzhar, Mudassir...
9页
查看更多>>摘要：The effects of dip treatment with beetroot peel extract on the quality of mahseer steaks during frozen storage (-18 degrees C) for 180 days were analysed. Prior to the dip treatment of steaks, the antioxidant properties of the extract were evaluated by in-vitro assays following the standard protocol. Beetroot peel extract was further evaluated for the characterisation of phenolic and flavanoid compounds by LC-MS/MS analysis. Beetroot peel extract (20 %, v/v) was used for the dip treatment based on the in-vitro antioxidant assay and preliminary sensory analysis. Quality changes in terms of chemical characteristics, drip loss, microbiological and sensory characteristics were examined at regular intervals of 30 days. A marked antioxidant and antimicrobial effect (P < 0.05) of beetroot peel extract could be detected in limiting the lipid oxidation and microbial growth in fish steaks during frozen storage. As per the scores of sensory analysis, control steaks had a shelf-life of about 5 months, whereas the BPE treated steaks were found to be acceptable for more than 6 months. Therefore, beetroot peel treatment exhibited positive effect on retarding the spoilage, thereby increasing shelf-life of mahseer steaks during frozen storage.
查看更多>>摘要：The effect of replacing commonly used hydrocolloids (i.e. xanthan (XTH), guar gum (GG), hydroxymethylcellulose (HPMC)) with psyllium on crumb texture, distribution of water populations and staling kinetics in gluten-free (GF) bread based on a blend of buckwheat and carob flour was studied. The addition of psyllium in GF formulation yielded bread with the softest and most resilient crumb. Psyllium was an effective anti-staling agent which significantly decreased the crumb hardening rate. The GF breads with psyllium and the hydrocolloids showed similar distribution of water populations, though psyllium tended to slightly increase their binding strength to the matrix. In the buckwheat/carob-based GF system, crumb firmness development was directly correlated to the amount of easily removable water population and inversely to the peak temperatures of strongly bound water which indicate higher bonding strength to the matrix. The results implied that psyllium and the tested hydrocolloids (i.e. XTH, GG, HPMC) can be interchangeably used to effectively control crumb texture and its evolution during storage of buckwheat/carob GF bread.
查看更多>>摘要：This study on raw ground beef patties evaluated: resistance of STEC strains inoculated at 6 log CFU/g (O157:H7, O26, O45, O103, O111, O121, and O145) subjected to 350, 450 and 600 MPa, for 5 min at 10 degrees C; effectiveness of pressure for initial loads (2, 3 and 4 log CFU/g) of 0157:H7; and general impact of high hydrostatic pressure (HHP) on raw patties. For 600 MPa treatments and 6 log CFU/g load of STEC, similar to 5 log CFU/g reductions were obtained with all strains. For 450 MPa, differences in bamresistance among strains became evident. When inoculating O157:H7 at different loads, counts after 600 MPa fell below quantification limits, though virulence genes were detected for the two highest loads. Additionally, HHP reduced native aerobic microbiota to <1 log CFU/g and slightly affected a* and b* color values. Montecarlo simulation was used to estimate potential initial counts of STEC that allow compliance with existing regulatory limits after applying HHP, showing that absence of STEC studied can be achieved in 65 g of patties provided initial loads are similar to 2 log CFU/g. Finally, HHP treatments at 600 MPa and mild temperatures can be considered a valid non-thermal processing technology to achieve 5 log CFU/g reductions.
查看更多>>摘要：Water, composed by hydrogen and oxygen elements, plays a prominent role in noodle production, especially in the sheeting process. To reveal the influence mechanism of water molecules movement on noodle qualities, several chemical interactions, gluten properties of the noodles sheeted by 1, 3 and 5 times were investigated in this study. The results of LF-NMR analysis showed that increased sheeting times confined the hydrogen protons mobility, and adjusted the composition proportion of hydrogen protons. These proton redistributions were captured by MRI and were correlated with the strongest hydrogen bonds and the most S-S content at 3 times of sheeting. Meanwhile, the stability and cohesiveness of the gluten network were enhanced, as reflected by increased beta-sheets, larger polymeric proteins and decreased end-points rate, which determined the cooking and texture properties changes. Overall, during the sheeting process, water molecules could participate in gluten network formation for regulating the noodle qualities through a series of chemical interactions.
查看更多>>摘要：Concentrated sugarcane juice (CSJ) is considered as one of the healthy sugar products, and so a potential feedstock in beverage formulations and soft drinks. However, irreversible aggregates, which are unattractive to the customer, are found with CSJ derived from the membrane filtration during storage. This study examined the formation of aggregates during the concentration of sugarcane juice to CSJ, and during CSJ storage. The concentration process for the formation of the aggregates goes by 3 stages, with polysaccharides interacting with phenolics and then proteins to form complexes which bind non-covalently to SiO2. For stored CSJ, inorganic compounds (mainly SiO2) were the main constituents in aggregates accounting for 43.14 % (w/w), followed by proteins, phenolics, polysaccharides, organic acids, and lipids. The results obtained with stored CSJ/NCS indicate that the proteins interact with phenolics and polysaccharides to form the flocs which then co-precipitate with SiO2 and calcium salts. The polishing of sugarcane juice with a multifunctional adsorbent in combination with the membrane filtration process could be a prospective approach solve the haze/aggregation problems associated with the CSJ, and further promotes their application in beverage formulations.
NSTL
Elsevier