Food Biotechnology
Rezvan Shaddel; Safoura Akbari-Alavijeh
Abstract
[1]Introduction: Today, the incidence of non-communicable and emerging diseases is increasing due to lifestyle changes, reduced mobility and changing dietary patterns. Some clinical evidences in simulated samples and real cases show that some compounds and plant extracts have a significant effect on ...
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[1]Introduction: Today, the incidence of non-communicable and emerging diseases is increasing due to lifestyle changes, reduced mobility and changing dietary patterns. Some clinical evidences in simulated samples and real cases show that some compounds and plant extracts have a significant effect on the prevention and even treatment of these diseases. On the other hand, due to the structural and functional diversity of plant polysaccharides, there is a great tendency among researchers to find new polysaccharides in different sources with new functional and bioactive properties. Despite extensive studies in this field, no study has been done on the extraction of polysaccharide compounds with prebiotic properties from green almond hull as one of the agricultural wastes. Therefore, the purpose of this study was to introduce a new type of synbiotic compound to balance clone microbiota and promote consumer health. Materials and methods: In this study, after extraction of water-soluble almond hull polysaccharides (AHP) by hot water extraction and precipitation with alcohol, the chemical analysis was done. To investigate the chemical composition of AHP, phenol sulfuric acid test was used to measure total sugar and Bradford test was used to measure protein. The amount of fat and ash in the sample was measured using standard methods (AOAC, 2005) and (AOAC, 2000), respectively. The amount of uronic acid of AHP was measured by calorimetry using metahydroxyphenyl at a wavelength of 520 nm. The content of AHP phenolic compounds was investigated by Folin Siocalcu calorimetric method. Fourier transform infrared (FT-IR) was also used to identify the functional groups and the anomeric status of AHP components. The prebiotic effect of this compound was also tested by digestion resistance and also by growth stimulation of the probiotic strain of Lactobacillus casei ATCC 393 in vitro for the first time. Results and discussion: Chemical analysis showed that AHP is a heteropolysaccharide consisting of 86.30% w/w of total sugar, 5.10% w/w protein and 3.21% w/w uronic acid. FT-IR analysis also confirmed the chemical structure of AHP as a heteropolysaccharide. The results of digestion resistance showed that 91.24% of AHP can remain stable and undecomposed after the stages of gastrointestinal digestion, while this rate was 74.94% for inulin as a commercial prebiotic. The second prebiotic property of AHP investigated in this study was the stimulation the growth of Lactobacillus casei ATCC 393 as probiotic in sugar-free MRS-based culture media and the results showed that AHP compared to inulin significantly increased the survival of Lactobacillus casei ATCC 393 (p <0.01). The proliferation index in media containing AHP and inulin showed a significant difference and AHP stimulated the growth of Lactobacillus casei ATCC393 significantly more than inulin (p <0.01). Therefore, to design a synbiotic product, if AHP is used as a prebiotic, the probiotic strain of Lactobacillus casei ATCC 393 would be a good choice.Considering the annual production of thousands of tons of almond green hull waste in Iran and the concerns related to environmental problems caused by its accumulation, the introduction of industrially feasible and economically justified methods to produce value-added products from this agricultural waste seems essential. In the present study, polysaccharides extracted from almond green hull by hot water extraction and alcohol precipitation, which is an economically feasible method and can be implemented on an industrial scale, were introduced as a useful compound. In vitro studies also used culture medium containing AHP as a commercial prebiotic in comparison with culture medium containing inulin. The results showed that this compound has a good resistance to digestive conditions in the gastrointestinal tract compared to inulin. The compound was also able to stimulate the growth of the probiotic Lactobacillus casei ATCC 393 in culture medium. In general, in this study, a new synbiotic compound including Lactobacillus casei ATCC 393 and AHP was introduced as a health beneficial food additive.
Seyed Mohsen Mortazavi; Hossein Jalali; Seyed Hamidreza Ziaolhagh
Abstract
In this study, the probiotic bacterium Lactobacillus acidophilus with different percentages of pomegranate peel powder (0, 0.5, 1, 1.5, and 2%) were used to produce a functional camel milk-based beverage. The physicochemical, antioxidant and sensory properties of the resulting drinks were evaluated. ...
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In this study, the probiotic bacterium Lactobacillus acidophilus with different percentages of pomegranate peel powder (0, 0.5, 1, 1.5, and 2%) were used to produce a functional camel milk-based beverage. The physicochemical, antioxidant and sensory properties of the resulting drinks were evaluated. The results showed that enrichment of milk with pomegranate peel powder improved the survival of probiotic bacteria from 6.95 to 7.35 Log CFU/ml. Addition of pomegranate peel to beverages increased their antioxidant activity from 7 to 85.33, 9.13 to 93.66 and 0.126 to 0.435 as measured by DPPH free radical scavenging, ABTS+ free radical scavenging and reduction potency tests, respectively. Rheological studies also showed that the addition of pomegranate peel powder to beverages increased their viscosity from 5.65 to 21.5 mPa. Adding pomegranate peel powder to beverages also changed the color factors (L*, a* and b*) so that increasing the level of pomegranate peel powder increased the red and yellow color in the samples. Also, the results of the sensory evaluation, including taste, appearance, smell and general acceptance indicated that the produced beverages were well-liked by consumers. However, the results of sensory evaluation showed that adding high percentages of pomegranate peel powder to beverages could reduce the sensory acceptance of the final product.
Ryhaneh Moghaddasi; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: The rheological properties of a bread dough describe its behavior under different process conditions. They are also central to its formulation, optimization, quality control, and better process capacity. A number of additives can improve the rheological properties of dough and breads. Fiber-based ...
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Introduction: The rheological properties of a bread dough describe its behavior under different process conditions. They are also central to its formulation, optimization, quality control, and better process capacity. A number of additives can improve the rheological properties of dough and breads. Fiber-based compounds and prebiotics in addition to gluten and starch, which have a large tendency to absorb the flour water, can affect the moisture distribution across the dough structure. Inulin and resistant starch are two types of prebiotics. Inulin is a water-soluble dietary fiber that is not absorbed by the enzymes at the upper section of he the digestive system and is partially fermented and metabolized by the microbial flora of the colon. Digestion-resistant starch is another prebiotic that acts as a food fiber and adds to the nutritional value. It can also improve the structure of the final product. In recent years, the rise in consumer awareness about health benefits of prebiotics has increased interests in functional foods particularly in bakery products. The present study qualitatively analyzed the effect of the prebiotics (i.e. inulin and resistant starch) on rheological properties of baguette bread doughs.
Materials and Methods: The study treatments are: Baking dough w/o inulin and resistant starch (Control); baking dough w 2.5% inulin (based on flour weight); baking dough w 5% inulin (based on flour weight); baking dough w 2.5% resistant starch (based on flour weight); baking dough w 5% inulin (based on flour weight); baking dough w 2.5% inulin + 2.5% resistant starch (based on flour weight); baking dough w 2.5% inulin + 5% resistant starch (based on flour weight); baking dough w 5% inulin + 2.5% resistant starch (based on flour weight); baking dough w 5% inulin + 5% resistant starch (based on flour weight). The treatments were rheologically tested by farinograph and extensograph after preparation. Study data were then analyzed using the completely randomized design. Means of data were also compared by Duncan's multiple-range test (α = 5%) in SPSS 16.
Results and Discussion: According to the results, the different levels of prebiotics (inulin and resistant starch) significantly improved dough water absorption compared to the control samples. This can be due to the presence of hydroxyl groups in the structure of the prebiotics, which increased the number of hydrogen bonds and thus water absorption in all treatments compared to the control. Moreover, these additives led to significantly higher dough development time than the control. This can be due to the hydroxyl groups in the structure of inulin and resistant starch, which increased the number of hydrogen bonds and thus cross-bonding with water. These additives also significantly increased the dough stability time compared to the control.This is a result of hydrogen attachments and hydroxyl bonding between gluten proteins (made up of glutenin and gliadin) and the prebiotics (inulin and resistant starch) that in turn improved the stability and strength of the doughs. As the dough stability increased, the dough softening degree after 10 and 12 minutes was also reduced, which was due to the hydrogen bonds resulting from hydroxyl cross-links of gluten with inulin and resistant starch. Note that the quality index increased when the stability and strength were improved compared to the control dough. According to the results, by adding different levels of inulin and resistant starch, the dough energy rised higher than the control sample after 45, 90 and 135 minutes. This is again due to (OH) hydroxyl bonds with hydrogen attachments between glutens and the prebiotics. In this regard, the highest resistance to extension after 45, 90 and 135 min was recorded for the treatments containing inulin and resistant starch whereas its lowest value was recorded for the control. This is due to the stable continuous lattice made by amylose in resistant starch granules, which led to the higher strength of other treatments than the control. Additionally, the increased dough resistance to extension can be due to the interaction of inulin and resistant starch with flour proteins. Regarding extensibility, significant differences were observed between the treatments and the control within all three time intervals. Accordingly, after 45, 90 and 135 min, the control treatment had the highest extensibility whereas the treatment with 5% inulin + 5% resistant starch (based on flour weight) had the lowest level of this parameter within these times. The increases in strength and stability of the doughs were caused by strong links between glutens and these prebiotics, which reduced the dough extensibility. The results showed that the highest dough ratio number after 45, 90 and 135 min belonged to the treatment with 5% inulin + 5% resistant starch (based on flour weight). The lowest ratio number was recorded for the control in these time periods. The gluten was the main factor behind dough stability. The large amount of hydroxyl groups in the structure of inulin and resistant starch led to formation of a better structured three-dimensional gluten lattice. In general, by taking all parameters into account, the treatment with 5% inulin + 5% resistant starch was selected as the best treatment.
Leila Goudarzi; Roha Kermanshahi
Abstract
Lactobacillus spp are a group of gram-positive, non-spore forming, cocci or rod shaped, catalase negative organisms that benefit to the host. prebiotics are non-digestible food ingredients that stimulate the growth and /or activity of bacteria in the digestive system in ways claimed to be beneficial ...
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Lactobacillus spp are a group of gram-positive, non-spore forming, cocci or rod shaped, catalase negative organisms that benefit to the host. prebiotics are non-digestible food ingredients that stimulate the growth and /or activity of bacteria in the digestive system in ways claimed to be beneficial to health. this study was conducted in order to investigate the effects of selected probiotic microorganisms in combination with prebiotics, on a growth or activity of proteus mirabilis. in this study the antimicrobial activity of five probiotic lactobacillus spp. (Lactobacillus acidophilus(atcc 4356), Lactobacillus Plantarum (ATCC 8014), Lactobacillus Fermentum (PTCC 1638), Lactobacillus Casei (PTCC 1608) And Lactobacillus Rhamnosus (PTCC 1637)) And Combination of probiotic and prebiotics (synbiotic) (Lactobacillus Spp. + five prebiotics : inulin, , trehalose , raffinose, lactulose and riboflavin) tested for their antimicrobial activity against proteus mirabilis (atcc 7002 and ptcc 1076) growth with agar well diffusion (awd) method. results showed that Lactobacillus Spp. had more antimicrobial activity against proteus spp., followed by inulin, , trehalose , raffinose , lactulose in comparison to basic mrs media (p
