جستجوی مقالات مرتبط با کلیدواژه "اثر ضد قارچی" در نشریات گروه "صنایع غذایی"

Simultaneous application of modern baking methods with fermented substrates is of great importance in controlling bread mouldiness. In the present study, predominant LAB was isolated from rice bran sourdough and after molecular identification, it was used as a starter culture in sourdough bread processing. In the next step, effect of using oven-infrared radiation, oven-supersaturated vapor and oven baking systems was investigated on the inhibition of surface mouldiness in produced breads. Sequencing results of the PCR products led to the identification of Pediococcus acidilactici. The lowest level of surface mouldiness with 27.06% was observed in bread containing controlled fermented rice bran baked in an oven-supersaturated vapor, which was significantly (P≤0.05) lower than the control sample. Wheat breads containing rice bran sourdough in all the three baking processes had less fungal surface expansion and more porosity, compared to the control bread. The highest amount of crumb hardness was belonged to wheat bread containing controlled fermented rice bran and baked with oven-supersaturated vapor, and the lowest hardness was related to the control bread baked with this process. The overall acceptability of the produced breads did not differ much from each other, and there was mainly no significant difference among them. Considering the appropriate techno-functional capabilities of the LAB isolated from fermented rice bran, it can be used as a protective starter culture in the fermentation industry. Using the infrared process in bread baking can be useful due to the relatively high baking speed and low energy consumption, antifungal effect and uniform heating.

Considering the sensitivity of apple fruit to many pests and diseases and the sensitivity of consumers to synthetic pesticides, the use of plant essential oils has increased to increase the lifespan of various horticultural products, including apples. In this research, total phenol, total flavonoid and antioxidant properties of Elettaria cardamomum essential oil were investigated. In addition, the antimicrobial property of this essential oil was evaluated on a number of fungi that cause spoilage of apple fruit, including Penicillium expansum, Botrytis cinerea, and Alternaria alternata. The phenol and flavonoid content of E. cardamomum essential oil was equal to 69.60 mg of gallic acid per gram of essential oil and 27.40 mg of quercetin per gram of essential oil, respectively. The amount of antioxidant property of E. cardamomum essential oil in DPPH and ABTS free radical inhibition method was obtained as 57.30% and 63.60%, respectively. In the investigation of the antifungal property, the largest inhibition zone was observed in P. expansum by disk diffusion and agar well methods, and the minimum inhibitory concentration for P. expansum and B. cinerea fungi was 8 mg/ml and minimum fungicidal concentration was 64 mg/ml. Considering the high antioxidant and antifungal properties of E. cardamomum essential oil, it can be used as a suitable alternative to synthetic fungicides.

Wheat bread is a staple food worldwide, and bread making using sourdough is one of the oldest technologies. In this regard, the use of legume sourdough is important in improving the quality of wheat bread. Sprouted legumes are also proper substrates rich in bioactive compounds for sourdough fermentation to produce enriched products. Furthermore, application of herbal extracts in sourdough formulation is a simple way to enhance organoleptic properties and mold-free shelf-life of the produced sourdough bread. Considering positive effects of sourdough on techno-functional properties of the produced bread, the aim of the present study was to enhance quality parameters of wheat bread using controlled fermented sprouted lentil containing fennel extract.

In the present study, predominant lactic acid bacteria (LAB) were isolated using the sequential back-slopping process from fermented sprouted lentil containing fennel extract.  The isolates were screened based on their antifungal activities against Aspergillus niger. The selected isolates were identified through amplification of the target sequence with 1500 bp from its 16S rDNA gene and sequencing of the PCR products. After that, controlled fermentation containing selected LAB isolates (as a starter culture) was performed in processing of wheat bread. Crumb hardness, specific volume, water activity, overall acceptability and surface growth rate of the target fungus were compared in the produced breads. In order to determine the effects of the substrate, fermentation and germination, suitable samples were produced. The results of the present study were also analyzed in a completely randomized design with three replications, and Duncan test at P<0.05 significant difference was used to compare the mean.

Sequencing results of the PCR products (amplicons) led to the identification of Pediococcus acidilactici as the selected LAB isolate. Addition of lentil sourdough to wheat bread significantly (P<0.05) reduced the weight loss and crumb hardness of wheat bread and also increased its specific volume without significant effect. Among the produced breads, the lowest specific volume was belonged to the sample containing lentil and the highest specific volume was observed in the control sample. Moreover, fermentation and sprouting reduced the surface growth of A. niger in the produced breads. The surface growth rate of the fungus in the bread containing fermented sprouted lentil was also significantly lower than those of the control sample. In addition, wheat bread containing fermented sprouted lentil received the highest overall acceptability score among the produced enriched breads. It is reported that the positive effects of controlled sourdough on textural features of the produced bread are mainly associated with the acidification activity of the starter culture used. Production of organic acids and other inhibitory metabolites by the sourdough starter culture is also involved in its antifungal activity in the product. Moreover, production of volatile and non-volatile aroma precursors during sourdough fermentation affect sensory attributes of the sourdough bread.   

Nowadays, consumer demand for healthy products with minimal processing and with no synthetic additives such as clean-label foods, and the use of bio-preservatives (application of microorganisms and their metabolites to prevent spoilage and increase the shelf-life of the product) has become a growing trend. Application of legumes as a good source of protein, other nutrients and essential components in bread formulation is important for their use in the daily diet. According to the results of the present study, controlled fermented sprouted lentil containing fennel extract can be used as an antifungal compound and texture improver in bakery industries. Overall, the use of plant extracts with antifungal effects as well as controlled fermentation of sourdough with selected LAB as protective/starter culture can reduce the use of chemical preservatives in bread.

The use of controlled fermented legumes along with the aqueous extract of aromatic plants is important in terms of improving the quality characteristics of wheat bread. In the present study, after spontaneous fermentation of mung bean sourdough containing saffron petal extract, the predominant lactic acid bacteria (LAB) isolate was used as a starter culture in controlled fermented sourdough, and then the characteristics of the produced wheat breads in terms of texture, surface expansion of fungi and overall acceptability were investigated. Sequencing results of PCR products led to the identification of Levilactobacillus brevis as the predominant LAB isolated from sourdough. Processing of wheat bread with mung bean sourdough containing mentioned bacteria and saffron petal extract not only improved the textural features and overall acceptability of the produced bread, but also increased their resistance towards the surface expansion of Aspergillus niger. Based on the results, wheat bread containing fermented mung bean and saffron petal extract showed the best textural features compared to other samples with crumb hardness of 10.21 N and porosity of 16.16%. Furthermore, the mentioned sample with 44.33% inhibition had the highest ability to inhibit the growth of the indicator fungus compared to other samples. Although the use of mung bean and saffron petal extract alone in the formulation of wheat bread did not show a great effect on reducing the surface expansion of fungi, but their combined application was significantly (P<0.05) effective in reducing the surface growth of fungus. Due to the appropriate techno-functional capabilities of controlled fermented mung bean sourdough containing saffron petal extract, it can be used as a natural improver in the bakery industries.

Prangos ferulacea is a plant that has been used in traditional medicine for its therapeutic properties. The present study was conducted to investigate the antifungal effect of P. ferulacea aqueous extract on Alternaria alternata, Alternaria solani, Saccharomyces cerevisiae, and Fusarium solani. The antifungal methods used were disc diffusion agar, well diffusion agar, minimum inhibitory concentration (MIC), and minimum fungicidal concentration (MFC). The extract concentrations used in the study were 20, 40, 60, and 80 mg/mL. The study found that the antifungal effect was concentration-dependent and increased with concentration. S. cerevisiae was the most sensitive species to the extract while F. solani was the most resistant. At 80 mg/mL, the inhibition zones for S. cerevisiae were found to be 11.90 mm and 13.00 mm in disc diffusion agar and well diffusion agar methods, respectively. The corresponding zones were 9.60 mm and 10.20 mm for F. solani, respectively. In the combined mode (interaction) of P. ferulacea aqueous extract with nystatin antibiotic, synergistic mode was observed for all fungal strains. The MIC and MFC values for S. cerevisiae were 32 and 128 mg/mL, respectively. The MIC and MFC results for F. solani were found to 256 and > 512 mg/mL, respectively. The results of this study showed that P. ferulacea aqueous extract could be used as a natural antifungal agent to inhibit the growth of pathogenic fungi on fresh fruits and vegetables.

Sourdough is a proper fermented ecosystem for isolation of lactic acid bacteria (LAB) with antifungal effects. In this research, dominant LAB isolated from rice bran and wheat bran sourdoughs were identified based on molecular method. Antifungal activity of the isolates and their cell free culture filtrate (CCF) obtained from logarithmic and stationary phases were also investigated based on overlay and spore spot methods respectively, against Aspergillus flavus and Aspergillus niger. According to sequencing the results of PCR products, Lactobacillus paraplantarum in wheat bran sourdough and Pediococcus pentosaceus in rice bran sourdough were identified as dominant isolated LAB. The results of overlay method also confirmed the inhibitory potential of the isolates against indicator fungi in comparison to control sample. Furthermore, inhibitory effect of the LAB isolates against A. flavus was significantly higher than the A. niger (P

The aim of this study was to identify the LAB strains isolated from Chal by the molecular method and to study antifungal activity of Lactobacillus brevis and Enterococcus faecium isolates as a biological preservative against Penicillium chrysogenum. The LAB isolates were identified using PCR technique with universal primers of LAB, sequencing of PCR products and comparing the sequencing results with the data available in NCBI. The antifungal effects were determined using overlay method to investigate the potential application of tested isolates as a biological preservative agent. Analysis of 16S rDNA gene sequences revealed two strains as L. brevis, one E. hirae and one E. faecium. The results of antifungal activity showed that both isolates of L. brevis and E. faecium had a strong inhibitory effect against P. chrysogenu so that the growth inhibition, after 48 hours, for strain C6 was more than the other strains. All treatments showed significant differences (P0.05) between treatments samples. Inhibitory percentage of both strains of L. brevis (C6 and C17) against P. chrysogenum was stronger than the strain of E. faecium (C8) against the mold. All treatments showed significant differences (P0.05) between the treatments samples. According to the results from present work can conclude that the tested isolates have a potential ability to prevent the microbial spoilage, in foods such as cheese that susceptible to spoil with P. chrysogenum, as natural and safe bio-preservative.