Mung Bean Sprouts Research Articles

Growth Responses of Clove Seedlings (Sizigium aromaticum L) to Natural Auxin and Household Waste Media

Indonesia is the number 1 clove producing country in the world, in amount of 140,812 tons (The Ministry of Indonesian Agriculture, 2022). Cloves are commonly used as a flavor enhancer for food and drinks. Its warm and spicy sensation is quite popular among people, especially those who live in cold areas. In addition, cloves are also useful for aromatic mixture of cigarettes. In addition, cloves are also good for the health of the body because they are known contain phosphorus, iron, magnesium, calcium, potassium, zinc, sodium and vitamins. This study aims were to determine the optimum concentration of organic auxin and the effect of using household waste media on the growth of clove plant seedlings. This study used a factorial experimental method which was arranged in a Completely Randomized Design (CRD) consisting of two factors. The first factor was the dose of household waste consisting of L0 = no household waste (control/ only with 2.5 g NPK fertilizer); L1 = household waste 10%; L2 = household waste 20% and L3 = household waste 30%. The second factor was the type of organic auxins, which consist of A0 = without organic auxin; A1 = red onion organic auxin; A2 = tomato organic auxin; A3 = auxin organic mung bean sprouts. Each treatment was repeated 4 times, resulting in 64 experimental units. The results showed that there was no interaction between the dose of household waste and natural auxins on the growth of clove seedling. Household waste can replace NPK fertilizer starting from a dose of 10 g/plant. Kinds of natural auxin did not affect the growth of clove seedlings. The seedling cultivation is enough profitable.

Metabolic profiling and expression analysis of key genetic factors in the biosynthetic pathways of antioxidant metabolites in mungbean sprouts.

Mungbeans (Vigna radiata L.), a major legume crop in Asia, contain higher amounts of functional substances than other legumes, such as catechin, chlorogenic acid, and vitexin. Germination can improve the nutritional value of legume seeds. Here, 20 functional substances were profiled in germinated mungbeans and the expression levels of the transcripts of key enzymes in targeted secondary metabolite biosynthetic pathways were identified. VC1973A, a reference mungbean elite cultivar, had the highest amount of gallic acid (99.93 ± 0.13 mg/100 g DW) but showed lower contents of most metabolites than the other genotypes. Wild mungbeans contained a large amount of isoflavones compared with cultivated genotypes, especially for daidzin, genistin and glycitin. The expression of key genes involved in biosynthetic pathways had significant positive or negative correlations with the target secondary metabolite contents. The results indicate that functional substance contents are regulated at the transcriptional level, which can be applied to improve the nutritional value of mungbean sprouts in molecular breeding or genetic engineering, and wild mungbeans are a useful resource to improve the quality of mungbean sprouts.

Nutritional Values of Biscuits and Kachari with Varying Concentrations of Germinated Wheat Flour, Pearl Millet Flour and Mung Beans Flour

Cluster fig, goolar in hindi, is a medicinal fruit, widely found in India. It is a rich source of iron and other micronutrients. Wheat is a staple food of Indian diet which is an energy dense food. It is a good source of carbohydrate & protein. Pearl Millet is most widely grown type of millet. It is known for its calorie value; vitamins & minerals present in it. Mung bean which belongs to the family of legumes has high calorie in it & is also a very good source of protein & poly-unsaturated fatty acid. For this study cluster fig powder, germinated wheat flour, germinated mung bean flour, germinated pearl millet, carrot powder & beetroot powder have been used. The product development was done using the above-mentioned ingredients. Two products with three treatments of varying quantity of ingredients was used for product development. The developed products undergone sensory and proximate analysis. Each treatment has three different replications to minimise the error during proximate analysis. Each product has three treatments for sensory evaluation and nutritional assessment with three different replications.
 The organoleptic evaluation highlight that the taste becomes bitter and the acceptability decrease with. Increased quantity of cluster fig. The proximate analysis concludes that with increase in the quantity of cluster fig, the iron and zinc content of the products increase. This study shed light on evaluation of organoleptic acceptability and nutritive & medicinal properties of cluster fig. It also provides idea on how much quantity of cluster fig powder & other ingredients should be used in various processed convenience healthy food. The research aims at highlighting the use of cluster fig which is widely available in India but has never been used to make convenience.

Synthesis of Green Cerium Oxide Nanoparticles Using Plant Waste from Colocasia esculenta for Seed Germination of Mung Bean (Vigna radiata)

Synthesis of cerium oxide (CeO2) nanoparticles (NPs) via biological approach has received a lot of interest to reduce the harmful effects of chemical synthesis. In the present study, Colocasia esculenta leaf extract facilitated the preparation of CeO2-NPs by using the sol-gel technique. The crystal structural of CeO2-NPs was proven by X-ray powder diffraction (XRD) investigation to be cubic with size of 2.94 nm according to Debye–Scherrer equation. As demonstrated in the transmission electron microscopy (TEM) image, CeO2-NPs have a spherical form with an average size of 2.04 nm which is almost consistent with a finding from XRD analysis. Energy dispersive X-ray (EDX) measurements exhibited high-intensity peaks attributed to Ce and oxygen and further proved the creation of CeO2-NPs. The Fourier transform infrared spectroscopy (FTIR) analysis revealed the presence of Ce-O stretching, indicating the formation of CeO2-NPs. Functional groups of O-H, C-O, and C=O peaks were found in a spectrum due to the phytochemical components that were responsible for reducing and stabilizing during the synthesis process of CeO2-NPs. The examined UV-visible spectra exhibited the absorbance peak at 213 nm. The synthesized NPs produced in this study were further investigated for mung bean seed germination, whereby the influence of grain germination and growth rate demonstrated the significant finding.

A "Turn-on" Fluorescent Probe Based on Phenothiazine for Selectively Recognizing ClO- and its Practical Applications.

Hypochlorous acid (HClO), a highly reactiveoxygen species, has important effects on human health. High selectivity and sensitivity remain challenges of fluorescent probes for detection of ClO- with a large Stokes shift. This work designed and synthesized a novel phenothiazine-based fluorescent probe TF which can detect ClO- by colorimetric and fluorescent dual signals. TF displayed turn-on fluorescence effect toward ClO- with high selectivity (≥ 28-folds) and sensitivity (LOD = 0.472μM), fast response time (< 1min) and large Stokes shift (150nm) in PBS (pH = 7.4, 40% DMSO). Meanwhile, TF can visualize ClO- on the mung bean sprouts model and apply as testing strips for portable and rapid detecting ClO- by the naked eyes. A phenothiazine-based fluorescent probe with large Stokes shift was synthesized and its responding rapidly ability to detect ClO- was studied.

Transcriptome and physiological determination reveal the effects of selenite on the growth and selenium metabolism in mung bean sprouts

Selenium (Se) biofortification of crops has been studied to substantially improve the Se content in human dietary food intake. In the present study, Vigna radiata (mung bean) seeds were soaked in different concentrations of sodium selenite (Na2SeO3). Low concentration of selenite is conducive to seed germination and growth, and can increase the fresh weight (FW) and dry weight (DW) of sprouts. The concentration of Na2SeO3 lower than 50 mg/kg resulted in noticeable elongation in the stem and marginal elongation in root. Mung bean seeds soaked with 80 mg/kg Na2SeO3 accounted for 93.77% of organic Se after growing for about 5 days. Transcriptome data revealed that Se treatment enhances starch and sugar metabolism, along with the up-regulation of ribosomal protein and DNA synthesis related genes. Further analysis indicated that the mung bean seeds absorbed Na2SeO3 through PHT1.1 and NIP2. Se (IV) was transformed into Se (VI) and transported to stems, leaves and roots through cotyledons during the germination of bean sprouts. SULTR3;3 may play an important role in the transit process. Se (VI) or Se (IV) transported to the leaves was catalytically transformed into SeCys through SiR and CS, and SeCys is further converted to MeSeCys through SMT. Most SeCys were transformed into SeHCys through CBL, transported to plastids, and finally transformed into SeMet through Met Synthase.

Stress-Resistance and Growth-Promoting Characteristics and Effects on Vegetable Seed Germination of Streptomyces sp. Strains Isolated from Wetland Plant Rhizospheres

Wetlands are the most biologically diverse ecosystems on Earth. The isolation of Streptomyces strains from wetlands is helpful to study their diversity and functions in such habitats. In this study, six strains of Streptomyces were isolated from the rhizosphere soil of three plant species in the Huaxi Wetland at Guiyang and were identified as Streptomyces galilaeus, S. avidinii, S. albogriseolus, S. albidoflavus, S. spororaveus, and S. cellulosae, respectively. The six strains all solubilized phosphate, fixed nitrogen, and produced ACC deaminase and siderophores, and four strains also secreted indole-3-acetic acid. The six strains had the ability to resist to certain degrees of salinity, drought, and acidic/alkaline pH stress. In addition, the S. avidinii WL3 and S. cellulosae WL9 strains significantly promoted seed germination of mung bean, pepper, and cucumber, especially the WL3 strain. A pot experiment further showed that WL3 significantly promoted the growth of cucumber seedlings. Thus, strains of six species of Streptomyces with multiple plant growth-promoting characteristics were isolated from the wetland. These results lay a foundation for their potential use as microbial agents for seed-coating treatments.

Effect of germination and eggshells nanocalcium fortification on characteristics of germinated mung bean drink (Vigna radiata.)

Germinated mung bean drinks with eggshell nanocalcium fortification are an alternative beverage to replace milk. This study aimed todetermine the effect of germination time and eggshells nanocalcium fortification on physicochemical characteristics of the germinated mungbean drink. This study used a Factorial Completely Randomized Design with two treatments factors. The first factor was germination timewhich consisted of three treatment levels (6, 12 and 18 hours) and the second factor was the type of eggshell nanocalcium which consistedof two type of treatment (chicken and duck eggshell), plus the control treatment as mung bean drink without germination and additionof eggshell nanocalcium. Each experiment was repeated three times. Observed parameters in this study were chemical characteristics(protein, calcium, vitamin C, and pH) and physical characteristics (viscosity and stability) of germinated mung bean drink. The resultsshowed that the germination time treatment significantly affected the value of protein, calcium, vitamin C, pH, viscosity, and stability ofthe germinated mung bean drink. Germination increased vitamin C in mung beans with an average value of 8,21-14,66 mg/100 g. Eggshellnanocalcium fortification showed a significant effect on increasing calcium of germinated mung bean drink. Germinated mung bean drinkproduced from 6 hours of germination and fortification of duck nanocalcium had the highest calcium content with value of 24.82%

THE EFFECT OF MUNG BEAN SPROUT EXTRACT AS A NATURAL PLANT GROWTH REGULATOR ON THE GROWTH OF SUGARCANE BUDCHIP (Saccharum officinarum L.) SEEDLINGS

This study aims to determine the effect of several concentrations of mung bean sprouts or bean sprouts extract on the growth of sugarcane bud chip seedlings, as well as to determine the most optimal concentration in stimulating the growth of sugarcane seedlings. Mung bean sprouts are known to contain the endogenous hormone auxin which can stimulate plant growth. This research was conducted using a non-factorial randomized block design. There are 5 concentration levels of bean sprout extract, including T0 (control), T1 (20%), T2 (40%), T3 (60%), T4 (80%). Parameters observed include the number of tillers, stem height, number of leaves, leaf length and root length. The results showed that bean sprout extract significantly affected the growth of seedlings from all parameters. The concentration of 20% bean sprout extract is the optimal concentration because it produces the highest number of tillers with an average of 8.80 tillers, the highest stem with an average of 18.00 cm, the largest stem diameter is 0.91 cm, the highest number of leaves is 8, 20 strands, the longest leaf is 73.3 cm, and the longest root is an average of 26.3 cm.

Effect of optimized germination technology on polyphenol content and hypoglycemic activity of mung bean.

The study aimed to investigate the effect of germination conditions on the content of polyphenol extract in mung bean and to further investigate the effect of polyphenol extract in germinated mung bean on diabetic mice. Through single factor experiment and response surface experiment, the effects of soaking temperature, soaking time, germination temperature, germination time and soaking liquid CaCl2 concentration on the polyphenol content of mung bean were analyzed. The optimal germination conditions of mung bean were determined as soaking temperature 25°C, soaking time 11 h, germination temperature 28°C, germination time 3 days and CaCl2 concentration 2 mM. Under these conditions, the content of polyphenol extract in germinated mung bean was 4.878 ± 0.30 mg/g, which was 3.07 times higher than that in ungerminated mung bean. The structure and content of purified polyphenols in germinated mung bean were determined by HPLC-MS/MS. Quinic acid, Quercetin, Rutin, Vitexin, Isovitexin and other substances were identified, and the content of polyphenols was 65.19%. In addition, through the in vivo and in vitro hypoglycemic activity experimental study of germinated mung bean polyphenols extract, the results showed that germinated mung bean polyphenols had an in vitro inhibitory effect on α-glucosidase, IC50 was 44.45 mg/ml. In vitro inhibitory activity was stronger after digestion. Polyphenol extract can significantly reduce blood sugar and improve insulin resistance in Type 2 diabetic mice (T2DM). According to the results, germination treatment is an effective way to increase the content of polyphenols in mung bean, and the polyphenols extract has hypoglycemic activity.

Design of a Bean Sprouts Device by Soilless Automatic Cultivation

In order to solve problems: the existing household bean sprouts cultivation device is relatively simple; bean sprouts are easy to be contaminated in the open cultivation tank which affects the quality of bean sprouts, and the automation is poor. The bean sprouts device by soilless automatic cultivation adopts cylindrical closed culture bin structure, and the temperature and humidity sensor is set in the culture bin, which can monitor the environment in real time. At the same time, the heating plate, fan and humidifier are set in the culture bin to heat up, cool down and humidify the environment, so as to realize automatic bean sprouts cultivation. The prototype test showed that: at the temperature 26°C-30°C, humidity 85%-95%, the diameter of mung bean sprouts can reach 2.5mm, and the height can reach 150mm. the diameter of yellow bean sprouts can reach 3mm, and the height can reach 160mm. The average yield of the two sprouts was 98%. The device has the advantages of soilless, intelligence, miniaturization and simple operation, which can meet the requirements of automatic bean sprouts cultivation. It is a necessary product for household in the future.

Study Functional Properties of the Isolated Protein from Germinated Mung

The functional properties of the defatted powder and protein isolate of germinated mung bean seeds were studied and the estimation of the amino acids was carried out. The results showed a significant increase in the values of the amino acids leucine, lysine, phenylalanine and valine. The results of studying the functional properties of the protein isolate and defatted powder showed that there were significant differences between the sample The defatted and protein isolate, if the water absorption capacity of the defatted mung powder was 2.5% water/gm protein and the water absorption capacity of the protein isolate was 3%ml water/g protein, the fat binding capacity of the defatted powder was 0.3 ml fat/g protein and the isolate The ratio was 1.7 ml of fat / g of protein. The ability of the protein isolates and the defatted powder to form foam was also studied. The effect of pH on the foam capacity and stability of the defatted mung bean seed powder and the protein isolate was also studied. The foam capacity at pH 4 showed high stability at 120 min. After the reaction, it reached 10%, while the pH 5 decreased its stability, reaching 8%, while the pH 7.6 showed a high stability, reaching (12, (13)%, respectively, and we note the stability of the foam in the protein isolate at pH 7.4, which amounted to (22.5,24)%, respectively.

The modulation of light quality on carotenoid and tocochromanol biosynthesis in mung bean (Vigna radiata) sprouts

This study aimed to identify the regulatory mechanisms of white, blue, red lights on carotenoid and tocochromanol biosynthesis in mung bean sprouts. Results showed that three lights stimulated the increase of the predominated lutein (3.2–8.1 folds) and violaxanthin (2.1–6.1 folds) in sprouts as compared with dark control, as well as β-carotene (20–36 folds), with the best yield observed under white light. Light signals also promoted α- and γ-tocopherol accumulation (up to 1.8 folds) as compared with dark control. The CRTISO, LUT5 and DXS (1.24–6.34 folds) exhibited high expression levels under light quality conditions, resulting in an overaccumulation of carotenoids. The MPBQ-MT, TC and TMT were decisive genes in tocochromanol biosynthesis, and were expressed up to 4.19 folds as compared with control. Overall, the results could provide novel insights into light-mediated regulation and fortification of carotenoids and tocopherols, as well as guide future agricultural cultivation of mung bean sprouts.

Effect of exogenous GABA combined with ultrasound treatment on the physicochemical and functional properties of sprouted mung bean starch

SummaryStarch is the major nutrient fraction in mung beans, wherein any physicochemical change in them while in germination as pre‐processing tactics influences their properties and hence application broadness. This study aimed to investigate the effect of ultrasonic synergistic exogenous GABA (γ‐aminobutyric acid) treatment on to the physicochemical and functional properties of mung bean starch during germination. At 96 h of germination, the total starch content was decreased to 21.18% and the amylose and resistant starch contents were 48.29% and 64.39% respectively. The particle size, colour, and water‐holding capacity of germinated mung bean starch were reduced significantly. As the increase in germination time continued, solubility, swelling and transparency increased and then decreased. The estimation of glycaemic index shows a minimum value of 22.52 at 12 h of germination. Combined treatment germination decreased the total starch content and increased the amylose and resistant starch content. The physicochemical properties of mung bean starch were significantly altered. Germination by ultrasound and exogenous GABA (γ‐aminobutyric acid) treatment modifies the functional properties of mung bean starch and provides a theoretical basis for its application in food.

The changes in Gamma-aminobutyric acid and polyphenols in mung beans (Vigna radiata L.) during germination

Gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, plays a role in regulating neuronal excitability. Polyphenols naturally occur in plants and help to prevent or reverse damage in cells caused by aging, the environment, and lifestyle. Edible sprouts such as mung beans are a valuable source that presents high content of bioactive compounds. These contents in raw mung beans are very low, but they increase significantly during germination. The objectives of this study were to determine the most appropriate germination conditions, including air relative humidity (80%, 90%, and 99%), salt concentrations (0, 0.5%, 1.0%, and 1.5%), and light conditions (dark, LED, and UV-C) during the soaking and incubation processes to maximize the content of GABA and polyphenols. The results showed that all investigated treatments (air relative humidity, salt, and light) increased GABA and polyphenol levels, but LED lighting and air relative humidity of 90% were the most effective. Under those conditions, the content of GABA and polyphenols in the germinated mung beans increased about 12 and 2 times, respectively. Furthermore, the changes in GABA and polyphenol contents were different under different soaking and incubation conditions. In conclusion, the nutritional quality of mung beans, in terms of GABA and polyphenols, could be improved by controlling light and air relative humidity during germination. It is also recommended that the germination conditions, including air relative humidity, soaking in water or salt, soaking time, and incubation time should be selected depending on the desired content of GABA or polyphenols.

Response Of Natural Zpt Generation Of Green Bean Sprouting Extract And Plant Media On The Growth Of Lemon Orange ( Citrus Limon L.) Plant Cuttings

From March to May 2021, this study was carried out in the Asahan University research facility. This study's goal was to ascertain how administering natural ZPT green bean sprout extract and planting media affected the growth of lemon plant cuttings ( Citrus limon L.). It was a randomized block design that was used (RBD). The first of the two components in the factorial treatment design is the administration of ZPT natural green bean sprout extract (Z) at four levels: Z 0 = no immersion, Z 1 = one hour of immersion, Z 2 = two hours of immersion, and Z 3 = three hours of immersion. The second factor is how growing media (M) are treated, with M 0 being moss and topsoil and M 1 being cocopeat and topsoil, and M 2 being chaff charcoal and topsoil, at three different levels. The proportion of live cuttings (%), the number of days before shoots appeared (days), the shoot height (cm), the number of leaves (strands), and the length of the roots were the parameters measured (cm). Almost all of the observed parameters, with the exception of the age at which shoots developed from cuttings, did not respond significantly to the administration of natural PGR extract of mung bean sprouts, according to the data. While this was going on, the treatment of the planting medium had a very big impact on the parameters of root length and leaf count that had been measured. In the meantime, the treatment of the planting medium had a very substantial impact on the parameters of root length, number of leaves, and shoot height that were measured. The percentage of live cuttings and the age at which shoots first developed, however, did not appear to have any discernible effects. Citrus limon L. cutting growth was not significantly affected by the interaction between the response of administering natural PGR extract of green bean sprouts and planting media, according to all measured parameters.

Towards Microbial Food Safety of Sprouts: Photodynamic Decontamination of Seeds

The climate crisis is one of the biggest challenges for humanity in the 21st century. Production and consumption of meat contributes to global warming by causing emissions of climate-relevant gases. Freshly grown sprouts are part of an alternative, as they are less polluting but still a nutritious food. However, warm humid sprouting conditions may cause pathogenic microorganisms to thrive. Decontamination methods for raw sprouts are therefore relevant. Photodynamic Inactivation (PDI) is a novel approach that uses photoactivatable molecules (photosensitisers, PS) and visible or near-infrared light to produce reactive oxygen species (ROS). These ROS kill microorganisms by oxidative processes. Here, we test the application of PDI based on sodium-magnesium-chlorophyllin (Chl, approved as food additive E140) for photo-decontamination of mung bean, radish, and buckwheat seeds. Seeds were contaminated with Listeria innocua, serving as a model system for Listeria monocytogenes, subjected to PDI using an LED array with 395 nm and tested for remaining bacterial contamination by CFU counting. PDI based on 100 µM Chl reduces the bacterial load of mung bean and radish seeds by 99.9% (radiant exposure 56.4 J/cm2 and 28.2 J/cm2, respectively), and of buckwheat seeds by &lt;90% reduction after illumination with 28.2 J/cm2. Neither weight nor the germination rates of seeds are affected by PDI. Interestingly, the effect of PDI on seeds is partially maintained on stored sprouts after germination: The bacterial load on mung bean sprouts is reduced by more than 99.9% after phototreatment of seeds with 100 µM Chl and illumination at 56.4 J/cm2. In conclusion, we suggest PDI based on Chl as an effective and biocompatible method for the decontamination of seeds and sprouts for human consumption from Listeria.

Assessment of electrohydrodynamic (EHD) pretreatment effects on functional and structural properties of protein isolate from sprouted mung bean

AbstractThis study aimed to investigate the effects of electrohydrodynamic (EHD) pretreatment on the functional properties of sprouted mung bean protein isolate (SMPI). Here, the effects of EHD voltage and time on the extraction yield (EY), protein solubility (PS), water‐holding capacity (WHC), oil absorption capacity (OAC), foaming capacity, and foaming stability of SMPI were evaluated. The results confirmed that the extracted SMPI at the EHD voltage of 20 kV had the highest EY, PS, WHC, OAC, and foaming properties. Furthermore, the EHD time of 40 min resulted in the production of SMPI with significantly high ES, PS, WHC, and foaming properties. The results of environmental scanning electron microscopy showed that increasing the EHD time to 40 min broke the protein cell structure. The more breaking occurs in the cell walls, the more protein extraction. Therefore, the application of EHD pretreatment as a green technique improves the functional properties of SMPI. EHD technique can be used as an applied and simple technique to improve the functional and structural properties of mung bean protein isolate in the food industry.Practical ApplicationsElectrohydrodynamic (EHD) is an environmentally friendly technique used to increase the heat and mass transfer rates in different processes. Sprout is one of the main mung bean products, an inexpensive source of proteins and nutrients for human health. In recent years, the consumption of sprouts has become more desirable due to their health benefits. Indeed, germination is a simple and effective process to transform raw seeds into useful products and enhance their nutritional quality. Moreover, germination increases the content of proteins, total dietary fiber, and phenolic compounds. Therefore, sprouts can be used as a more appropriate protein source, and it is better to extract proteins from sprouted seeds. Therefore, EHD is a green process with improved functional properties of sprouted mung bean protein isolate, which can be used as an ingredient in food products.

Tissue-Specific Metabolic Profiling of Mungbean (Vigna radiata L.) Genotypes with Different Seed Coat Colors

Mungbean (Vigna radiata L.) is one of the major legume crops containing high carbohydrate and protein contents. In this study, the total phenolic and flavonoid contents and ABTS/DPPH radical scavenging activity of whole sprouts and seed coats were evaluated by using 10 mungbean genotypes with diverse seed coat colors and origins. Qualitative/quantitative analysis of individual secondary metabolites was performed with ultrahigh performance liquid chromatography (UPLC). Overall, 23 polyphenols, including flavonoids, phenylpropanoids, and anthocyanins, were identified. Depending on genotypes, significant variations in the contents of each phytochemical were identified before/after germination. The results indicate that the specific pathways of phenolic compounds, including chlorogenic acid, coumestrol, genistein, and glycitein, are activated by sprouting in mungbean. The neo/chlorogenic acid contents had tissue specificity, even though it was isomeric. The anthocyanin contents were higher in green and yellow mungbeans than in black mungbeans. These findings in this study will provide valuable information to improve the food quality of mungbean sprouts with high polyphenolic contents.

Use of a phage cocktail to reduce the numbers of seven Escherichia coli strains belonging to different STEC serogroups applied to fresh produce and seeds

AbstractThe aims of this research were to evaluate the effectiveness of a phage cocktail at reducing seven Shiga toxigenic Escherichia coli (STEC) serogroups on different food matrixes: mung bean sprouts (MBP), lettuce, and mung bean seeds (MBS) and to test the phage cocktail effectiveness to reduce E. coli O157 on Romaine and iceberg lettuce. To study the effect of the type of food matrix on the STEC phage cocktail effectiveness, a mixture of seven highly sensitive STEC strains designated as phage propagation strains (PPS) were used to adulterate Romaine lettuce, MBP, and MBS matrixes at a concentration of 105 logs CFU/g. A subsample of the treated MBS was germinated to assess STEC survival. Recovered STEC strains were confirmed using latex agglutination and PCR. To test the phage cocktail effectiveness to reduce E. coli O157:H7 on Romaine and iceberg lettuce, a mixture of four STEC strains (different than phage propagation strains, non‐PPS) at both low (103 CFU/g) and high (105 CFU/g) concentrations were used to spike the samples in scaled up trials for the purpose of potential commercialization. Phage treatments including a combination of STEC phage cocktail and chlorinated water treatment were then applied to lettuce in a simulated scaled‐up trial. STEC was assessed on the treated samples at different storage time and temperatures (0, 24, 48, and 72 hr at 2, 10 and 25°C). In the food matrix trial, the combination of STEC phage cocktail and chlorinated water‐reduced PPS (p &lt; 0.001) STEC on lettuce by 2.1 log10 CFU/g and on MBP by 2.2 log10 CFU/g. However, isolates from all 7 STEC serogroups remained viable after phage treatment in both lettuce and MBP; particularly those associated with serogroup O111, O121, O103, and O145, while only a few colonies of serogroup O26, O45, and O157 were detected. Lettuce adulterated with low levels of 4 non‐PPS E. coli O157:H7 (103 CFU/g) achieved a reduction of 2.6–3.2 logs. While a reduction 1.7–2.3 logs was achieved by the phage cocktail when lettuce was inoculated with 105 CFU/g. Overall phage performance was more effective at 2 and 10°C and improved over storage time up to 72 hr. However, for MBS, the phage cocktail was not able to kill any of the STEC populations as all of them recovered during germination.