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1.
ABSTRACT:  Defatted flour, protein concentrate, and protein isolate obtained from Amazonian cupuassu seeds were evaluated for their solubility properties, water and oil retention capacity, foam formation and stability, gelling properties, emulsifying ability, and emulsion stability. The protein contents of defatted flour, the concentrate, and the isolate were 27.65%, 31.18%, and 64.29%, respectively. As expected, the protein isolate exhibited higher solubility than the protein concentrate, achieving more than 90% solubility at pH 8.0. The flour and the protein concentrate, however, showed excellent water and oil retention capacities. High emulsifying capacity at pH 7.0 was also observed for all 3 products: 987 mL oil/g, 977 mL oil/g, and 1380 mL oil/g for the flour, protein concentrate, and protein isolate, respectively. Gelling properties were not exhibited by any of the products, but all of them exhibited good utilization potential, not only to enrich other foods but also to enhance relevant functional properties.  相似文献   

2.
The cocoa relatives T grandiflorum (cupuaçu) and T bicolor (macambo) are promising crop plants for sustainable agroforestry in the Amazon region of South America. The market for cupuaçu is expanding since the fruit flesh is utilised by the foodstuffs industry. Attempts to commercialise chocolate‐like wares from the seeds have failed so far because of unreliable product quality. It is not known whether this is due to an insufficient aroma potential of cupuaçu seeds. We therefore investigated the proteolytic enzymes and the seed storage globulins which are both decisive for the formation of aroma precursors in cocoa. We found that the activities of the aspartic endopeptidase and the carboxypeptidase in T bicolor and T grandiflorum differed slightly from those in cocoa. The specificity of the carboxypeptidase for hydrophobic amino acids was quite similar across the three species, while the optimal pH of the T grandiflorum enzyme was lower than that of the other species. The qualitative and quantitative differences between the globulins indicate a lower maximum yield of aroma precursors in T grandiflorum and a higher maximum yield of aroma precursors in T bicolor, compared to cocoa. We conclude that the quality of chocolate‐like products made from the studied cocoa relatives can be improved by adapting fermentation procedures to particular biochemical features of these seeds. Copyright © 2004 Society of Chemical Industry  相似文献   

3.
Abstract: The use of nanoparticles in food packaging has been proposed on the basis that it could improve protection of foods by, for example, reducing permeation of gases, minimizing odor loss, and increasing mechanical strength and thermal stability. Consequently, the impacts of such nanoparticles on organisms and on the environment need to be investigated to ensure their safe use. In an earlier study, Moura and others (2008a) described the effect of addition of chitosan (CS) and poly(methacrylic acid) (PMAA) nanoparticles on the mechanical properties, water vapor, and oxygen permeability of hydroxypropyl methylcellulose films used in food packaging. Here, the genotoxicity of different polymeric CS/PMAA nanoparticles (size 60, 82, and 111 nm) was evaluated at different concentration levels, using the Allium cepa chromosome damage test as well as cytogenetic tests employing human lymphocyte cultures. Test substrates were exposed to solutions containing nanoparticles at polymer mass concentrations of 1.8, 18, and 180 mg/L. Results showed no evidence of DNA damage caused by the nanoparticles (no significant numerical or structural changes were observed), however the 82 and 111 nm nanoparticles reduced mitotic index values at the highest concentration tested (180 mg/L), indicating that the nanoparticles were toxic to the cells used at this concentration. In the case of the 60 nm CS/PMAA nanoparticles, no significant changes in the mitotic index were observed at the concentration levels tested, indicating that these particles were not toxic. The techniques used show promising potential for application in tests of nanoparticle safety envisaging the future use of these materials in food packaging.  相似文献   

4.
The aim of this paper was to characterize chitosan samples from the shrimp shells for the later development of antimicrobial active systems. These systems include 100 % chitosan-based films obtained by casting, polyamide films with 5 and 10 % of chitosan obtained by extrusion and polyethylene/polyethylene terephthalate films with a coating of 0.6 % of chitosan. For that purpose, several analytical techniques including IR, 1H NMR, GPC, and microscopic techniques (scanning electron microscopy and transmission electron microscopy) were used. Within the studied samples, C1 showed the lowest DA and MW and consequently presented the most suitable properties for the development of an active packaging. Additionally, mechanical properties were performed. The effectiveness of the developed systems was evaluated by means of microbiological assays. The tested films showed antimicrobial capacity against coliform enterobacteria, mesophilic aerobic microorganism, and yeast and moulds.  相似文献   

5.
In this study, silver (Ag), zinc oxide (ZnO), and copper oxide (CuO) metallic nanoparticles were used in preparation of carboxymethyl cellulose (CMC) nanobiocomposite films. Scanning electron microscopy (SEM), X‐ray diffraction (EDXA), water vapor permeability (WVP), ultraviolet and visible light (UV–Vis) spectroscopy, and mechanical and microbial tests were used to determine the characteristics of the obtained active films. SEM results showed that the CMC nanobiocomposite films had roughness deflection levels and the EDXA test confirmed the presence of Ag, ZnO, and Cuo nanoparticles in the biopolymer tissue. UV–Vis spectroscopy confirmed that with addition of metallic nanoparticles to the pure CMC film, absorption rate increased and WVP decreased. In the mechanical tests, addition of nanoparticles also increased the tensile strength of the films, and the nanobiocomposite films exhibited higher resistance compared to the pure CMC film. Films incorporating metallic nanoparticles showed antibacterial properties against Escherichia coli and Staphylococcus aureus growth. Thus, nanobiocomposite films can be used as active packaging films and could increase the shelf‐life of the food.  相似文献   

6.
7.
Edible active coatings (EACs) based on pectin, pullulan, and chitosan incorporated with sodium benzoate and potassium sorbate were employed to improve the quality and shelf life of strawberries. Fruits were washed, disinfected, coated by dipping, packed, and stored at 4 °C for 15 d. Application of EACs reduced (P < 0.05) weight loss and fruit softening and delayed alteration of color (redness) and total soluble solids content. In contrast, pH and titratable acidity were not affected (P > 0.05) throughout storage, and ascorbic acid content was maintained in pectin‐EAC coated strawberries. Microbiological analyses showed that application of EACs reduced (P < 0.05) microbial growth (total aerobic counts, molds, and yeasts) on strawberries. Chitosan‐EAC coated strawberries presented the best results in microbial growth assays. Sensory quality (color, flavor, texture, and acceptance) improved and decay rate decreased (P < 0.05) in pectin‐EAC, pullulan‐EAC, and chitosan‐EAC coated strawberries. In conclusion, EACs based on polysaccharides improved the physicochemical, microbiological, and sensory characteristics, increasing the shelf life of strawberries from 6 (control) to 15 d (coated fruits).  相似文献   

8.
Although the demand for goat milk products has been growing, they have lower consumer acceptability than products derived from cow milk. However, the addition of cupuassu pulp can be used to improve the formulation of these products. For this reason, the aim of this study was to investigate the influence of new goat milk yogurt manufactured with cupuassu pulp on physicochemical properties, consumers’ perceptions, and overall consumer acceptance. In addition, the effect of antioxidant health information on consumer acceptance and purchase intention of cupuassu goat milk yogurts was evaluated. The results demonstrated a positive expectation regarding linking and familiarity to goat milk products and products with cupuassu pulp. The pH, total phenolic content, lightness, redness, yellowness, and apparent viscosity were potentially affected by the addition of cupuassu, with the highest concentration of cupuassu (10%) exhibiting the greatest changes in parameters. Based on principal component analysis, partial least squares regression, and just-about-right and penalty analysis, the addition of cupuassu pulp improved some sensory attributes of goat milk yogurt, such as cupuassu aroma, cupuassu flavor, yellow color, consistency, and viscosity, which positively influenced product acceptance. In addition, antioxidant health information increased the acceptance and purchase intention of cupuassu goat milk yogurts. Taking into account the parameters investigated in this study, the best scoring formulation was goat milk yogurt with 10% cupuassu pulp. Our results suggest that cupuassu pulp can be considered a potential ingredient to improve the sensory and texture properties of goat milk yogurt. Furthermore, the antioxidant health information could be a sensory strategy to increase the acceptance of cupuassu goat milk yogurts.  相似文献   

9.
ABSTRACT: Edible films can incorporate antimicrobial agents to provide microbiological stability, since they can be used as carriers of a wide number of additives that can extend product shelf life and reduce the risk of pathogenic bacteria growth on food surfaces. Addition of antimicrobial agents to edible films offers advantages such as the use of low antimicrobial concentrations and low diffusion rates. The aim of this study was to evaluate inhibition of Aspergillus niger and Penicillium spp. by selected concentrations of Mexican oregano (Lippia berlandieri Schauer) essential oil added to amaranth, chitosan, or starch edible films. Oregano essential oil was characterized by gas chromatography-mass spectrometry (GC/MS) analysis. Amaranth, chitosan, and starch edible films were formulated with essential oil concentrations of 0%, 0.25%, 0.50%, 0.75%, 1%, 2%, and 4%. Mold radial growth was evaluated inoculating spores in 2 ways: edible films were placed over inoculated agar, Film/Inoculum mode (F/I), or the edible films were first placed in the agar and then films were inoculated, Inoculum/Film mode (I/F). The modified Gompertz model adequately described growth curves. There was no significant difference (P > 0.05) in growth parameters between the 2 modes of inoculation. Antifungal effectiveness of edible films was starch > chitosan > amaranth. In starch edible films, both studied molds were inhibited with 0.50% of essential oil. Edible films added with Mexican oregano essential oil could improve the quality of foods by controlling surface growth of molds.  相似文献   

10.
The purpose of this study was to investigate the effect of packaging film on physicochemical properties, microbial profile, and biogenic amines content of barramundi (Lates calcarifer Bloch) fillets packed in polyamide, polypropylene, and low-density polyethylene films and kept at 8°C more than 20 days under modified atmosphere packaging. Putrescine and cadaverine were the most abundant amines, whereas the concentration of histamine ranged from less than 0.5 (not detected) to 198.0, 264.3, and 308.5 mg/kg for polyamide, polypropylene, and polyethylene (low-density polyethylene) films, respectively. Among the three, the psychrotrophic bacteria count was initially 4.26 log colony forming units/g and exceeded the acceptable limit of 7 log colony forming units/g on the 16th day of storage for polyamide and on 12th day of storage for polypropylene and polyethylene. However, the total plate count, among the three packaging films, was initially 3.54 log colony forming units/g and exceeded the acceptable limit of 6 log colony forming units/g on the 12th day of storage. The histamine-forming bacteria count was significantly (p < 0.05) lower in barramundi fillets packaged with polyamide compared to polypropylene and polyethylene. The significant difference (p < 0.05) was observed between the concentration of amines in polyamide as compared with polypropylene and polyethylene. Among the three packaging materials, polyamide was found to be the best for prolonging the storage of barramundi fillets.  相似文献   

11.
Pulverization is a potentially powerful solution for the resource management of surplus- and non-standard agricultural products, maintaining their nutritional values for long and ensuring their homogeneity, whereas their original textures could disappear to narrow the application ranges. Therefore, new technologies should be developed for reconstructing the powders to provide them with new physical characteristics. Herein, we developed a novel food material, nata puree (NP), by nata de coco (bacterial cellulose gel) disintegration with a water-soluble polysaccharide using a household blender. The process worked well with (1,3)(1,4)-β-glucan (BGL) as the polysaccharide, which could be substituted with barley extract. Lichenase treatment of the NP dramatically modified its physical properties, suggesting the importance of the BGL polymeric forms. NP exhibited distinct potato powder and starch binding activities, which would be attributed to its interactions with the cell wall components and a physical capture of powders by the NP network, respectively. NP supplementation into the potato paste improved its firmness and enabled its printable range shift for 3D food printing to a lower powder-concentration. NP also promoted the dispersion of powders in its suspension, and designed gelation could also be successfully performed by the laser irradiation of an NP suspension containing dispersed curdlan and turmeric powders. Therefore, NP could be applied as a powder modifier to a wide range of products in both conventional cooking, food manufacturing, and next generation processes such as 3D food printing.  相似文献   

12.
Novel protein sources (like insects, algae, duckweed, and rapeseed) are expected to enter the European feed and food market as replacers for animal‐derived proteins. However, food safety aspects of these novel protein sources are not well‐known. The aim of this article is to review the state of the art on the safety of major novel protein sources for feed and food production, in particular insects, algae (microalgae and seaweed), duckweed, and rapeseed. Potential hazards for these protein sources are described and EU legislative requirements as regard to food and feed safety are explained. Potential hazards may include a range of contaminants, like heavy metals, mycotoxins, pesticide residues, as well as pathogens. Some safety aspects of novel protein sources are intrinsic to the product, but many potential hazards can also be due to production methods and processing conditions. These aspects should be considered in advance during product development. European law is unclear on several issues regarding the use of novel protein sources in food and feed products. For food product applications, the most important question for food producers is whether or not the product is considered a novel food. One of the major unclarities for feed applications is whether or not products with insects are considered animal‐derived products or not. Due to the unclarities in European law, it is not always clear which Regulation and maximum levels for contaminants apply. For market introduction, European legislation should be adjusted and clarified.  相似文献   

13.
欧盟RASFF系统食品风险预警的数据分析研究   总被引:3,自引:0,他引:3  
欧盟成员国在预防食品和饲料的安全问题时,愈来愈重视和依靠欧盟的食品与饲料快速预警系统(RASFF),该系统已经成为欧洲地区保障食品安全重要的信息交流平台。自2001年伊始,欧盟RASFF系统每年发布一次年度报告,2009年已经涉及到全球121个国家。本文以RASFF系统的年度报告为基础,根据2008年以来的数据,分析RASFF系统的信息报告种类、关注的热点问题和重大事件、针对中国的报告等,以及数据所表征的风险变化、趋势和欧洲食品安全新的预警进展。  相似文献   

14.
15.
对滚筒干燥法制备的、马口素铁充氮罐装的婴幼儿谷类辅助食品保质期进行预测研究。通过设计加速破坏性试验,应用化学品质衰变动力学模型于婴幼儿谷类辅助食品。依据营养素在加速试验期内的衰减情况推断产品在室温条件下的保质期。试验结果表明:该类婴幼儿谷类辅助食品水分活度值在0.2~0.3之间,有利于产品的保存。在4~5个月的加速试验期内,营养素不饱和脂肪酸二十二碳六烯酸(DHA)和花生四烯酸(AA)的衰变率最大。依据各营养素指标变化值预测产品在室温条件下保质期为20个月以上。  相似文献   

16.
The present evaluation aimed to synthesis and characterise the Pogostemon cablin essential oil encapsulated chitosan nanoemulsion (PCEO-CN) and evaluated its antifungal antimycotoxin and antioxidant activities. A total of twenty-six different chemical compounds were identified from P. cablin essential oil (PCEO), among which patchoulol (34.93%), α-bulnesene (17.76%) and α-guaiene (15.44%) were recorded as major components. The average size of PCEO-CN was 18.20 nm. The PCEO-CN showed concentration-dependent broad-spectrum antifungal and antimycotoxin activities. The in vivo evaluation showed that PCEO-CN significantly protected maize seeds from mould-induced biodeterioration and aflatoxin B1 biosynthesis for up to 30 days. The PCEO-CN significantly inhibits ergosterol biosynthesis and cellular integrities of A. flavus. Based on the present study, PCEO-CN could be used as a food preservative to control mould and mycotoxin contamination in stored maize.  相似文献   

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