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Latex fractions from Calotropis procera, Cryptostegia grandiflora, Plumeria rubra, and Himatanthus drasticus were assayed in order to prospect for new plant peptidases with milk-clotting activities, for use as rennet alternatives. Only C. procera and C. grandiflora latex fractions exhibited proteolytic and milk-clotting activities, which were not affected by high concentrations of NaCl and CaCl2. However, pre-incubation of both samples at 75 °C for 10 min eliminated completely their activities. Both proteolytic fractions were able to hydrolyze k-casein and to produce peptides of 16 kDa, a similar SDS-PAGE profile to commercial chymosin. RP-HPLC and mass spectrometry analyses of the k-casein peptides showed that the peptidases from C. procera or C. grandiflora hydrolyzed k-casein similar to commercial chymosin. The cheeses made with both latex peptidases exhibited yields, dry masses, and soluble proteins similar to cheeses prepared with commercial chymosin. In conclusion, C. procera and C. grandiflora latex peptidases with the ability to coagulate milk can be used as alternatives to commercial animal chymosin in the cheese manufacturing process. 相似文献
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《Food chemistry》1987,26(1):71-79
Yield, chemical composition and texture profile of cheese made with vegetable rennet from sodom apple leaves were compared with those of a direct acid cheese made with calf rennet. Yield, moisture, fat and protein contents were 14·47%, 49·70%, 26·15% and 20·0%, respectively, for cheese made with vegetable rennet and 12·45%, 44·80%, 29·84% and 20·4%, respectively, for the direct acid cheese made with calf rennet. Cheese made with vegetable rennet had less soluble nitrogen than that made with calf rennet despite the fact that vegetable rennet was more proteolytic in casein solution than calf rennet. Relative to that made with calf rennet, cheese made with vegetable rennet was harder, less cohesive and more gummy, presumably because of differences in chemical composition and physical characteristics between the cheeses. 相似文献
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A milk clotting enzyme with low proteolytic activity was extracted with ammonium sulfate, at 0.40-0.65 saturation, from sodom apple leaves. The enzyme with apparently a basic isoelectric point was activated by cysteine and was more active at 65°C than at 35°C. Milk clotting activity increased with pH at 65°C, with the enzyme being almost twice as active at pH 6.4 as at pH 5.4-5.7. Storage at 4°C for 15 days resulted in a 30-50% loss in enzyme activity. 相似文献
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研究工业大麻叶对单增李斯特菌的抑菌成分及抑菌机理,为其在食品工业中作为天然防腐剂的可能提供理论参考。工业大麻叶醇提后依次经乙酸乙酯萃取、硅胶柱分离,利用微量肉汤稀释法测定最低抑菌浓度并筛选高活性组分,气相色谱-质谱联用分析其有效成分;通过比较菌体细胞壁完整性、细胞膜通透性、能量代谢和氧化损伤变化以及扫描电镜观察,探讨抑菌机制。工业大麻叶乙酸乙酯萃取组分经体积比为1∶1的石油醚-乙酸乙酯洗脱后所得组分Fr.1:1对单增李斯特菌抑菌效果最好,最低抑制浓度为62.5 μg/mL,共鉴定出亚麻酸甲酯(40.79%)、十六酸甲酯(13.12%)等24种挥发性化合物;经Fr.1:1处理后,细菌表面有明显破溃,胞外碱性磷酸酶活性升高,培养液电导率增大,胞内三磷酸腺苷含量和超氧化物歧化酶活性均先升后降。工业大麻叶Fr.1∶1可破坏单增李斯特菌细胞壁和细胞膜结构,导致细胞通透性增加,电解质外泄,进而影响菌体能量代谢并造成质膜氧化损伤,最终使细菌生长受到抑制。 相似文献
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Mohamed Makni Anissa Haddar Walid Kriaa Najiba Zeghal 《International Journal of Food Properties》2013,16(4):756-765
The antioxidant capacity, total phenolics, flavonoids, and condensed tannin contents of Ajuga iva leaf extracts obtained with different solvent polarities were investigated. The antibacterial and antifungal proprieties were also studied using different microorganisms. The methanol extract with the highest amounts of total phenolics and flavonoids showed the highest antioxidant activities in all assays, followed by the aqueous chloroform and hexane extracts, respectively. The methanol extracts of Ajuga iva exhibited promising antibacterial and antifungal activities, indicating that Ajuga iva leaves might be used in further investigations for developing new antioxidants. 相似文献
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ABSTRACT: Successive chloroform, ethanol, and ethyl acetate partitions of extracts from Cynara scolymus L. leaf, head, and stem were tested for their antimicrobial activity against 15 microbial species, including 7 foodborne bacterial pathogens, Bacillus subtilis, Staphylococcus aureus, Agrobacterium tumefaciens, Micrococcus luteus, Escherichia coli, Salmonella typhimurium , and Pseudomonas aeruginosa , 4 yeasts, Candida albicans, Candida lusitaniae, Saccharomyces cerevisiae , and Saccharomyces carlsbergensis , and 4 molds, Aspergillus niger, Penicillium oxalicum, Mucor mucedo , and Cladosporium cucumerinum using the disk diffusion assay technique. The leaf extract was found to be most effective against all of the tested organisms, followed by the head and stem extracts, and the ethanol fraction showed the most significant antimicrobial activity against all of the tests among 3 soluble fractions of extract, followed by the chloroform and ethyl acetate fractions. The minimum inhibitory concentrations (MICs) of extracts determined by the agar and broth dilution method ranged from 1.25 to 10.0 mg/mL. The MIC of ethanol fraction of leaf extracts was the lowest by comparison with the other 2 extracts. The MIC for fungi was at or below 2.5 mg/mL and for bacteria was at or above 2.5 mg/mL. 相似文献
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Nurain Aziman Noriham Abdullah Zainon Mohd Noor Wan Saidatul Syida Wan Kamarudin Khairusy Syakirah Zulkifli 《Journal of food science》2014,79(4):M583-M592
Preliminary phytochemical and flavonoid compounds of aqueous and ethanolic extracts of 6 aromatic Malaysian herbs were screened and quantified using Reverse‐Phase High Performance Liquid Chromatography (RP‐HPLC). The herbal extracts were tested for their antimicrobial activity against 10 food‐borne pathogenic and food spoilage microorganisms using disk diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of herbal extracts were determined. In the phytochemical screening process, both aqueous and ethanolic extracts of P. hydropiper exhibited presence of all 7 tested phytochemical compounds. Among all herbal extracts, the aqueous P. hydropiper and E. elatior extracts demonstrated the highest antibacterial activity against 7 tested Gram‐positive and Gram‐negative bacteria with diameter ranging from 7.0 to 18.5 mm and 6.5 to 19 mm, respectively. The MIC values for aqueous and ethanolic extracts ranged from 18.75 to 175 mg/mL and 0.391 to 200 mg/mL, respectively while the MBC/MFC values for aqueous and ethanolic extracts ranged from 25 to 200 mg/mL and 3.125 to 50 mg/mL, respectively. Major types of bioactive compounds in aqueous P. hydropiper and E. elatior extracts were identified using RP‐HPLC instrument. Flavonoids found in these plants were epi‐catechin, quercetin, and kaempferol. The ability of aqueous Persicaria hydropiper (L.) H. Gross and Etlingera elatior (Jack) R.M. Sm. extracts to inhibit the growth of bacteria is an indication of its broad spectrum antimicrobial potential. Hence these herbal extracts may be used as natural preservative to improve the safety and shelf‐life of food and pharmaceutical products. 相似文献
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Antimicrobial Effects of Silver Nanoparticles Synthesized by Fatsia japonica Leaf Extracts for Preservation of Citrus Fruits 下载免费PDF全文
Jing Zhang Guoguo Si Jun Zou Ruiliang Fan Ailing Guo Xuetuan Wei 《Journal of food science》2017,82(8):1861-1866
Due to their potent antimicrobial activity, silver nanoparticles (AgNPs) synthesized by biomass might be promising in food preservation, whereas effects of AgNPs on Penicillium italicum‐induced rot of Citrus fruits have not been investigated. In this study, a novel AgNPs biosynthesis method was developed based on Fatsia japonica leaf extracts. It was revealed that concentrations of leaf extracts, AgNO3 and NaCl affected AgNPs yields and particle sizes obviously. Under the optimized conditions (8 mg/mL extracts, 2 mM AgNO3 and 1 mM NaCl), AgNPs, synthesized within 80 min, showed potent preservative effect against P. italicum‐induced rot of Citrus fruits. Furthermore, inhibition test and TEM analysis indicated that as‐synthesized AgNPs caused cell deformation, cytoplasmic leakage, and thereupon cell death of P. italicum. Moreover, AgNPs had significant antibacterial activities against Escherichia coli and Staphylococcus aureus, which might be beneficial for Citrus fruits preservation. Altogether this study develops an efficient AgNPs synthesis method and a novel preservation method for Citrus fruits. 相似文献
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以金针菇粗提物的不同萃取相为材料,以大肠杆菌、产气杆菌、枯草芽孢杆菌、金黄色葡萄球菌、蜡状芽孢杆菌和啤酒酵母为供试菌,通过抑菌圈法和生长速率法探讨金针菇粗提物体外抑菌活性;并以金黄色葡萄球菌和大肠杆菌为供试菌,研究金针菇不同萃取相抑菌稳定性。结果表明,金针菇不同萃取相对金黄色葡萄球菌均有较强的抑制作用,乙酸乙酯相有显著的抑菌活性。同时,金针菇不同萃取相对革兰氏阳性菌的抑菌活性强于革兰氏阴性菌。金针菇不同萃取相对金黄色葡萄球菌的MIC范围是3.25 mg/m L~12.5 mg/m L,MBC范围是3.25 mg/m L~12.5 mg/m L。并且金针菇不同萃取相的抑菌活性对温度、紫外光的稳定性较好。可以作为一种保健食品(饮品)进一步开发利用。 相似文献
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Gholamreza Kavoosi Asad Tafsiry Ali Asghar Ebdam Vahid Rowshan 《Journal of food science》2013,78(2):T356-T361
Carum copticum and Ferula assafoetida have several medicinal properties including antispasmodic, carminative, sedative, analgesic, and antiseptic. Reactive oxygen species (ROS), reactive nitrogen species (RNS), hydrogen peroxide (H2O2), and thiobarbituric acid reactive substances (TBARS) scavenging activities of Carum and Ferula oils along with their antibacterial and antifungal activities were examined. Thymol (40.25%), γ‐terpinene (38.7%) and p‐cymene (15.8%) were detected as the main components of Carum oil while, β‐pinene (47.1%), α‐pinene (21.36%), and 1, 2‐dithiolane (18.6%) were the main components of Ferula oil. Inhibitory concentrations (IC50) for total radical scavenging were between 40 and 60 and 130 and 160 μg/mL of Carum and Ferula oil, respectively. Minimal inhibitory concentration (MIC) for Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger, and Candida albicans were 78 ± 8, 65 ± 7, 14 ± 3, 5 ± 2, 5.6 ± 1.3, and 8.8 ± 2.2 μg/mL of Carum oil, respectively. MIC for S. typhi, E. coli, S. aureus, B. subtilis, A. niger, and C. albicans were >200, >200, 125 ± 17, 80 ± 12, 85 ± 5, and 90 ± 11 μg/mL of Ferula oil, respectively. Accordingly, Carum and Ferula oils could be used as safe and effective natural antioxidants to improve the oxidative stability of fatty foods during storage and to preserve foods against food burn pathogens. Practical Application : This study clearly demonstrates the potential of Carum and Ferula oil especially Carum oil as natural antioxidant and antimicrobial agent. The chemical composition of essential oils was identified. Thus, identification of such compounds also helps to discover of new antioxidant, antibacterial and antifungal agents for potential applications in food safety and food preservation. 相似文献
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目的:研究松针不同提取物的抑菌作用。方法:用水和乙醇对马尾松松针进行提取,通过平板抑菌试验,比较水提物和醇提物、老叶提取物和幼叶提取物以及混合提取物的抑菌作用,分析pH值对提取物抑菌作用的影响,并比较提取物与常用食品防腐剂抑菌作用的差异。结果:在对多数指示菌的抑制作用上,松针水提物比醇提物效果明显,幼叶提取物比老叶提取物作用强,对食品中常见腐败细菌的抑制作用较好,对真菌和酵母的抑制作用较弱;松针提取物在酸性环境下能很好地发挥其抑菌活性;在试验条件下松针提取物抑菌效果比山梨酸钾和苯甲酸钠明显。结论:松针提取物具有良好的抑菌作用,可作为一种天然食品防腐剂资源。 相似文献
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Višnja Katalinic Sonja Smole Mozina Ivana Generalic Danijela Skroza Ivica Ljubenkov Anja Klancnik 《International Journal of Food Properties》2013,16(1):45-60
The phenolic composition, antioxidant activity, and antimicrobial activity of extracts from vine leaves of six grape varieties collected in May, August, and September was studied. The phenolic potential of the extracts was dependent on variety and picking-time. Extracts of leaves collected in September were the richest in total phenols, flavonoids, flavonols, and stilbenes. The antioxidant properties determined by ferric reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl assays, and antimicrobial activity against Stapylococcus aureus, Bacillus cereus, Campylobacter jejuni, Escherichia coli, and Salmonella Infantis were good and in correlation with the chemical composition changes of the leaf extracts. The results indicated that leaves remaining on the vine in September after the grape harvest could be especially promising as an inexpensive source of effective antioxidant/antimicrobial agents. 相似文献
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Dionysios Christodouleas Kyriakos Papadopoulos Antony C. Calokerinos 《Food Analytical Methods》2011,4(4):475-484
A sensitive and simple method is described for the evaluation of total antioxidant activity of olive and seed oils and their
corresponding aqueous and organic extracts based on the chemiluminescent reaction of lucigenin with hydrogen peroxide. The
method was fully validated for precision, trueness, robustness, additivity, and uncertainty. Validation results demonstrated
that the method is able to measure the antioxidant activity of untreated edible oils as well as their hydrophilic and lipophilic
extracts and posses all necessary quality factors required for routine analysis. Comparison of results with those obtained
by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and Folin–Ciocalteu methods has indicated a significant correlation between them.
Furthermore, it was found that extra virgin olive oils exhibit two to three times higher total antioxidant activity than refined
olive oils and seed oils, and the contribution of antioxidant activity of organic and aqueous extracts of oils to the corresponding
total antioxidant activity is significantly different in olive oils than seed oils. 相似文献
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M. R. Szabo D. Radu S. Gavrilas D. Chambre C. Iditoiu 《International Journal of Food Properties》2013,16(3):535-545
Tinctures of eleven plants used as spices (basil, celery, dill, horsetail, lovage, marjoram, milfoil, oregano, parsley, rosemary, and thyme) were tested for their antiradical properties by means of the DPPH (1,1-diphenyl-2-picrylhydrazyl) assay over a two year period. Seven of these plants (basil, lovage, marjoram, milfoil, oregano, rosemary and thyme) were selected to obtain a mixture, which was tested in situ as antioxidant on vegetable and animal fats by an accelerated oxidation test at 110°C. The herbal extract also showed antimicrobial activity against Staphylococcus aureus (ATCC 25923), Streptococcus pyogenes (ATCC 49399), Escherichia coli (ATCC 25922) and Candida albicans (ATCC 24433). 相似文献
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芦荟提取物抑菌作用的研究 总被引:26,自引:4,他引:22
用芦荟提取物对几种常见的微生物进行抑菌活性测定,结果表明芦荟提取物能有效地抑制细菌的生长,对供试菌的最低抑菌浓度金黄色葡萄球菌为10%,沙门氏菌为8%,大肠杆菌为9%,产气肠杆菌9%,枯草杆菌11%,芦荟提取物能耐受高温短时的热处理。 相似文献