Sprout Production Research Articles

Abundance of liana species in an Amazonian forest of Brazil reflects neither adventitious root nor foliar sprout production

Abstract:Liana abundance and size have increased in neotropical forests. High vegetative reproductive capacity (clonality) may be the cause of high abundance in some liana species. Correlations between vegetative propagation capacity and (1) relative abundance of liana species, (2) rooting and foliar sprouting potentials of congeneric species, and (3) phylogenetic position were determined. Species selection was based on the relative abundance of lianas in ten 0.5-ha parcels in continuous forest within the Biological Dynamics of Forest Fragments Project (BDFFP), Brazil. Five individuals per species were replicated with seven cuttings per individual. Cuttings placed in moistened sand and coconut fibre were observed for 5 mo in a humid greenhouse. Survival percentage, rooting percentage, potential regeneration index and longest root length were determined per species. The two most abundant species (9.3% and 4.1% relative abundance) had low vegetative regeneration capacity, contrary to expectations. However, a significant, positive relationship between vegetative propagation and relative abundance of liana species whose relative abundances were <4% was found. Congeneric species showed no difference in vegetative propagation between rare and abundant species, except congeners of Machaerium. Vegetative reproductive capacity occurred in all major evolutionary lineages, but was highest in Fabaceae and Bignoniaceae, families of high abundance both locally and broadly across Neotropical forests.

Effect of some Media on Artichoke Sprouts Production and Nutritional Values

Sprouts are excellent source of, amino acids, enzymes, minerals, phytochemicals and vitamins which are the most useful compounds for the human health. This study aimed to investigate the effect of three germination media (soil mixture consisted of soil + vermiculite + 10 % compost, rice straw and kitchen paper towel) on the production and nutritional value of sprouts artichoke comparing with artichoke heads. The highest sprouts yield was produced on soil mixture. On the other hand, based on dry weight, the comparison among sprouts produced on the different media, indicted that sprouts produced on kitchen paper towel showed the highest values of the most nutritional. Meanwhile, sprouts produced on kitchen paper towel exhibited significantly value higher contents of protein, total lipid, inulin, total sugars, calcium, sodium, phosphorus, antioxidants, the essential amino acids (such as leucine, isoleucine, threonine, phenylalanine and valine) than detected in artichoke heads. Reversely, artichoke heads significantly value higher contents of fibers, carbohydrates, phosphorus, vitamin A, vitamin C, total phenols, chlorogenic acid, cynarin, and the essential amino acid aspartic than all sprouts. The essential fatty acids (linoleic acid, linolenic acid) were determined in sprouts produced on soil mixture and rice straw, but they were not found in artichoke heads and produced on kitchen paper towel. According to the current results, it is recommended to collect artichoke seeds, before they are scattered in the soil at the end of the season, to be used in producing sprouts throughout the year as a source of healthy food and a protection from various serious diseases.

Pathogen reduction on mung bean reduction of Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes on mung bean using combined thermal and chemical treatments with acetic acid and hydrogen peroxide

Mung bean sprouts were implicated in several foodborne outbreaks worldwide in recent years. The objectives of this study were to (i) assess the efficacy of individual (mild heat) and combined treatments (mild heat followed by acetic acid or/and hydrogen peroxide) for the inactivation of enteric bacterial pathogens on mung bean intended for sprout production and (ii) determine the impact of the treatments and storage conditions on germination. Mung bean was co-inoculated with Escherichia coli O157:H7, Salmonella enterica and Listeria monocytogenes to achieve initial populations of approximately 5–6 log CFU of each species/g bean. The inoculated bean was then subjected to eight different treatments immediately after inoculation and after four weeks of storage at 22 °C. Selective media were used to estimate residual populations of each pathogen after treatment and subsequent to germination. The results showed that all combined treatments achieved a minimum 3-log CFU/g reduction in E. coli O157:H7, S. enterica and L. monocytogenes on freshly inoculated bean. The combined treatment with hot water followed by exposure to H2O2 and acetic acid resulted in a > 3-log reduction on mung bean stored for four weeks. The bactericidal effect of the combined treatments was significantly (P < 0.05) impacted by the duration of treatment and bean storage time. These data suggest that the combined use of mild heat, acetic acid and H2O2 may serve as a choice for organic sprouts industry in the disinfection of mung bean.

Survival of Salmonella during Production of Partially Sprouted Pumpkin, Sunflower, and Chia Seeds Dried for Direct Consumption

Ready-to-eat foods based on dried partially sprouted seeds have been associated with foodborne salmonellosis. Whereas research has focused on the potential for Salmonella initially present in or on seeds to grow and survive during fresh sprout production, little is known about the potential for growth and survival of Salmonella associated with seeds that have been partially sprouted and dried. The goal of this study was to determine the growth of Salmonella during soaking for partial germination of pumpkin, sunflower, and chia seeds and subsequent survival during drying and storage. Pumpkin, sunflower, and chia seeds were inoculated with a four-serotype Salmonella cocktail by the dry transfer method and were soaked in sterile water at 25 or 37°C for 24 h. During the soaking period, Salmonella exhibited growth rates of 0.37 ± 0.26, 0.27 ± 0.12, and 0.45 ± 0.19 log CFU/h at 25°C and 0.94 ± 0.44, 1.04 ± 0.84, and 0.73 ± 0.36 log CFU/h at 37°C for chia, pumpkin, and sunflower seeds, respectively. Soaked seeds were drained and dried at 25, 51, and 60°C. Drying resulted in >5 log CFU/g loss at both 51 and 60°C and ∼3 log CFU/g loss at 25°C on partially sprouted pumpkin and sunflower seeds. There was no decrease in Salmonella during drying of chia seeds at 25°C, and only drying at 60°C provided losses >5 log CFU/g. Dried seeds were stored at 37 and 45°C at 15 and 76% relative humidity (RH) levels. The combination of temperature and RH exerted a stronger effect than either factor alone, such that rates at which Salmonella decreased generally followed this order: 37°C at 15% RH < 45°C at 15% RH < 37°C at 76% RH < 45°C at 76% RH for all seeds tested. Rates differed based on seed type, with chia seeds and chia seed powder having the smallest rate of Salmonella decrease, followed by sunflower and pumpkin seeds. Drying at higher temperatures (50 and 61°C) or storing at elevated temperature and humidity (45°C and 76% RH) resulted in significantly different rates of Salmonella decrease.

Fate of Salmonella enterica and Enterohemorrhagic Escherichia coli Cells Artificially Internalized into Vegetable Seeds during Germination.

Vegetable seeds contaminated with bacterial pathogens have been linked to fresh-produce-associated outbreaks of gastrointestinal infections. This study was undertaken to observe the physiological behavior of Salmonella enterica and enterohemorrhagic Escherichia coli (EHEC) cells artificially internalized into vegetable seeds during the germination process. Surface-decontaminated seeds of alfalfa, fenugreek, lettuce, and tomato were vacuum-infiltrated with four individual strains of Salmonella or EHEC. Contaminated seeds were germinated at 25°C for 9 days, and different sprout/seedling tissues were microbiologically analyzed every other day. The internalization of Salmonella and EHEC cells into vegetable seeds was confirmed by the absence of pathogens in seed-rinsing water and the presence of pathogens in seed homogenates after postinternalization seed surface decontamination. Results show that 317 (62%) and 343 (67%) of the 512 collected sprout/seedling tissue samples were positive for Salmonella and EHEC, respectively. The average Salmonella populations were significantly larger (P < 0.05) than the EHEC populations. Significantly larger Salmonella populations were recovered from the cotyledon and seed coat tissues, followed by the root tissues, but the mean EHEC populations from all sampled tissue sections were statistically similar, except in pregerminated seeds. Three Salmonella and two EHEC strains had significantly larger cell populations on sprout/seedling tissues than other strains used in the study. Salmonella and EHEC populations from fenugreek and alfalfa tissues were significantly larger than those from tomato and lettuce tissues. The study showed the fate of internalized human pathogens on germinating vegetable seeds and sprout/seedling tissues and emphasized the importance of using pathogen-free seeds for sprout production.IMPORTANCE The internalization of microorganisms into vegetable seeds could occur naturally and represents a possible pathway of vegetable seed contamination by human pathogens. The present study investigated the ability of two important bacterial pathogens, Salmonella and enterohemorrhagic Escherichia coli (EHEC), when artificially internalized into vegetable seeds, to grow and disseminate along vegetable sprouts/seedlings during germination. The data from the study revealed that the pathogen cells artificially internalized into vegetable seeds caused the contamination of different tissues of sprouts/seedlings and that pathogen growth on germinating seeds is bacterial species and vegetable seed-type dependent. These results further stress the necessity of using pathogen-free vegetable seeds for edible sprout production.

Enrichment of gamma-aminobutyric acid in bean sprouts: Exploring biosynthesis of plant metabolite using common household reagents.

The enrichment of plant foods with gamma-aminobutyric acid (GABA) is currently an interesting issue in the field of nutraceuticals and can be used as an experiment for upper-division undergraduate students. Here, an interdisciplinary hands-on experiment to produce GABA-enriched mung bean sprouts using common household reagents is described. Based on the GABA biosynthesis pathways, two key factors, being the availability of l-glutamic acid and the acidification of the germination environment, were chosen for the study of the effects on the enhancement of GABA levels. The activities not only led students to a deeper understanding of biochemistry contents, but also gave the students the opportunity to work with experimental design, analytical chemistry, and statistical data analysis. Furthermore, since mung bean sprouts are familiar foods and the reagents used for germination are easily obtainable and generally recognized as safe, the optimal protocol investigated in the lab could be further applied to the production of bean sprouts with enhanced nutritional values in everyday life, promoting the transfer of knowledge learned in school to practical environments such as home and community. © 2017 by The International Union of Biochemistry and Molecular Biology, 46(2):155-161, 2018.

Enhanced sprout-regeneration offsets warming-induced forest mortality through shortening the generation time in semiarid birch forest

Abstract Warming-induced mortality and a decline in regeneration potential have recently been observed in semiarid forests. To understand future forest dynamics, studies have begun to examine the long-term resilience of semiarid forests against climate change. Previous research has documented a relatively high resilience through seedling production for patchy coniferous forests at the arid timberline compared to continuous and arid tree line forests. However, it remains unclear whether broad-leaved forests in semiarid regions share the same pattern and how they work. In this study, we observed a similar nonlinear pattern in forest resilience along a local aridity gradient by reconstructing the regeneration history and investigating post-mortality regeneration in white birch-dominated (Betula platyphylla) forests in semiarid Inner Asia. Changes in regeneration modes from seedling to sprout production accelerated the white birch regeneration process and speeded up tree replacement. High competition from abundant recruits enhanced both forest resilience and resistance to climate change in arid timberline forests. However, only weak resilience was observed in birch forests at the arid tree line, which stopped regeneration and meant that old trees dominated the age structure. This might increase the risk of hydraulic failure. Our results implied that the decline in regeneration potential was not consistent in semiarid regions. Although forest mortality increased along with aridity, some broad-leaved forests at the arid timberline have a high resilience because they generate abundant sprouts to compensate for the losses from forest mortality. This study shows that a similar resilience pattern occurs under the impact of climate change and that various resilience mechanisms are affected by the different biological features of coniferous and broad-leaved forests in Inner Asia, which have important implications for future forest dynamics in semiarid regions and provide scientific background for managing this vulnerable forest and important insights into persistence of forests in semi-arid Inner Asia.

Treatment of Wastewater from Bean Sprout Production for Reuse

Bean sprout production consumes a significant volume of municipal water and generates a similar amount of wastewater. Water costs become a serious concern for this food industry, therefore wastewater reuse is highly desired by many sprout producers. Bean sprout wastewater has a relatively low level of contamination, which gives a great potential for reuse. The objective of this study was to exam the treatment feasibility of sprout production wastewater using a membrane bioreactor. Real-world wastewater from a sprout producer was treated continuously for 35 days. Important water quality parameters were monitored closely including chemical oxygen demand (COD), ammonia, tannins, pH, total suspended solids (TSS), etc. Once the biological system was stabilized, the MBR’s effluent showed very low level of COD, ammonia, TSS and bacteria, which demonstrated that the reuse of sprout wastewater is achievable.

적콜라비 새싹채소 종자에서 분리한 Escherichia coli strain RC-4-D의 생장예측모델

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and 30°C). Baranyi model was used as a primary order model for growth data. The maximum growth rate (μmax) and lag-phase duration (LPD) for each temperature (except for 10°C LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

Salvage logging of mountain birch after geometrid outbreaks: Ecological context determines management outcomes

Abstract Outbreaks of pest insects occasionally cause mortality of entire forest stands. Salvage logging of affected stands is the most common management response to such events. Logging may aid stand recovery by increasing the production and establishment of saplings, or stimulating the production of basal sprouts in sprouting tree species. However, the outcome of logging may depend on the ecological context in which it is implemented, with both herbivory and local growing conditions being potentially important factors. We conducted a field experiment to assess how logging affects recovery by saplings and sprouts in stands of mountain birch that have been damaged by outbreaks of geometrid moths. The study was conducted at the two locations Luftjok and Bugoyfjord in subarctic Norway, where moth outbreaks have caused widespread mortality of mountain birch during the last two decades. Logging generally caused a strong increase in the production of basal sprouts, and also improved sprout growth in Luftjok, resulting in a substantial production of new stems in the logging plots at this location within the six-year period of the study. In Bugoyfjord, sprout growth was retarded in logging plots compared to controls, resulting in complete failure to produce new stems during the study period. This appears to have been caused by ungulate browsing, possibly in interaction with regional, geologically determined, gradients in growing conditions. The outcome of logging also depended on local site quality, with limited sprouting occuring in rich meadow type stands, which traditionally have been assumed to have low capacity for sprout production. Birch saplings were less abundant in logging plots than in controls by the end of the study, especially in Bugoyfjord, suggesting that logging did not improve sapling production. We conclude that logging may stimulate damaged mountain birch stands to recover by means of basal sprouting, but that the positive effects of logging may be reduced by browsing in some areas. Logging should also be practiced with care in rich meadow type stands, which have limited capacity for sprouting.

Evaluation of important seed and sprout traits as potential selection criteria in breeding varieties for sprout soybeans

Soybean sprouts, a traditional vegetable in Asia, are gaining popularity in the United States. Soybean sprout demand has been supplied by natto (a Japanese soyfood) cultivars that share some seed characteristics with sprout cultivars. However, natto seeds do not meet all requirements of sprouts and are rejected by sprout manufacturers. The objectives of this study were to evaluate important seed and sprout traits as potential selection criteria in breeding sprout soybeans and to study the storage effect on soybean sprout quality. Almost all genotypes produced thicker and longer hypocotyls and higher fresh-sprouts than ‘MFS-561’, a commercial soybean sprout variety. Hypocotyl length ranged from 13.8 to 16.2 cm. Four fungi genera Bipolaris sp., Cercospora sp., Botrytis sp. and Caethomium sp. were isolated from seeds. Cracked cotyledons and abnormal seedlings were the two main constraints affecting soybean sprout quality. Correlation coefficients among all traits indicated that percentage and weight of high- and average-quality sprouts would determine sprout yield. Acceptable yield and several traits were recommended to be used simultaneously while breeding superior sprout soybean cultivars. Good sprout varieties should produce high-quality sprouts >48%, average-quality sprouts 5.7 g/g seed, hypocotyl thickness >1.6 cm and hypocotyl length >13 cm. One-year seed storage at room temperature reduced sprout quality. V09-3876 and V12-1939 had superior seed and sprout traits and are promising lines for further evaluation for sprout production. Seed storage over time affects seed germination and seedling vigor, and fungi on seed can cause reduced seed quality.

Influence of sprouting environment on the microbiota of sprouts

AbstractSprouts are popular for health conscious and vegetarian consumers; however, this produce item has been associated with frequent foodborne outbreaks. To understand the influence of the sprouting environment on the microbiota colonizing the sprout, microbial populations of both sprouting seeds and sprouts were characterized using terminal fragment length polymorphism analysis. The dominant microbial populations on mung bean, alfalfa, and broccoli seeds over the course of germination were compared to the microbiota of commercially grown sprouts that were grown from seeds from the same distributer. Regardless of the initial population, similar organismal families were found on all final sprout varieties and was primarily composed of Pseudomonadaceae. Commercially germinated sprout varieties had lower abundances of Pseudomonadaceae for all three varieties, and housed more diverse microbial families, such as Bacillaceae, Sphingomonadaceae, Phyllobacteriacae, and Lactobacillaceae.Practical applicationsObservations from this manuscript can be used to better understand the impact the sprouting environment has on the microbial population of the final sprout product. The microbiota of sprout varieties, as described in this manuscript, may help understand microbial spoilage factors of sprout products. By understanding the microbial populations of sprouts, the observed benefits of sprouting seeds/beans in previously used sprout water and the use of competitive exclusion techniques can progress forward.

Development of a novel multiplexed qPCR and Pyrosequencing method for the detection of human pathogenic yersiniae

The purpose of this study was to develop a novel and robust molecular assay for the detection of human pathogenic yersiniae (i.e. Yersinia enterocolitica, Y. pseudotuberculosis and Y. pestis) in complex food samples. The assay combines multiplexed real-time PCR (qPCR) and Pyrosequencing for detecting and differentiating human pathogenic yersiniae with high confidence through sequence based confirmation. The assay demonstrated 100% specificity and inclusivity when tested against a panel of 14 Y. enterocolitica, 22 Y. pestis, 24 Y. pseudotuberculosis and a diverse selection of 17 other non-Yersinia bacteria. Pyrosequencing reads ranged from 28 to 40bp in length and had 94–100% sequence identity to the correct species in the GenBank nr database. Microbial enrichments of 48 ready-to-eat foods collected in the Greater Toronto Area from March 2014 to May 2014, including 46 fresh sprout and 2 salad products, were then tested using the assay. All samples were negative for Y. pestis and Y. pseudotuberculosis. Both salads (n=2) and 35% of sprout products (n=46) including 7.1% of alfalfa sprouts (n=14), 81% of bean sprouts (n=16), 12% of mixed sprouts (n=8) tested positive for Y. enterocolitica which was not detected in broccoli sprouts (n=5), onion sprouts (n=1), and pea sprouts (n=2). Cycle thresholds (Ct) of positive samples for Y. enterocolitica were between 23.0 and 37.9 suggesting post enrichment concentrations of approximately 1×102 to 1×106Y. enterocolitica per 1mL of enriched broth. An internal amplification control which was coamplified with targets revealed PCR inhibition in five samples which was resolved following a one in ten dilution. Pyrosequencing of qPCR amplicons suggests monoclonality and revealed a single nucleotide polymorphism that is present in Y. enterocolitica biotype 1A suggesting low pathogenicity of the detected strains. This study is the first to combine Pyrosequencing and qPCR for the detection of human pathogenic yersiniae and is applicable to a broad range of complex samples including ready-to-eat food samples.

Effects of Iron Enrichment of Adzuki Bean (Vigna angularis) Sprouts on Elemental Translocation, Concentrations of Proteins, Distribution of Fe-Metalloproteins, and Fe Bioaccessibility

Iron (Fe) is an essential element for human nutrition, and its deficiency or low hemoglobin levels are a global health issue. Strategies aimed at increasing the amounts of essential elementals in agricultural products, as sprouts of adzuki bean (Vigna angularis), can be a way to minimize deficiencies, mainly in the populations of developing countries. Therefore, in this work was evaluated: production of Fe-enriched adzuki bean sprouts; Fe accumulation and translocation in plants in different culture media enriched with different Fe masses (500, 1000, 2000, and 3000 µg); and effects of the enrichment by means of 3000 µg FeIII-ethylenediaminetetraacetic acid (FeIII-EDTA): on the distribution of Ca, Cu, Fe, K, P, Mg, S, and Zn in different parts of the plant; on protein concentrations (albumins, globulins, prolamins, and glutelins) and their association with Fe in edible parts of the plant (stems); and on Fe bioaccessibility in the edible part of the plant (stems). The enrichment via FeIII-EDTA favored the translocation and increased Fe content of sprouts (75%), besides promoting interactions of Fe with albumins (141%), globulins (180%), and glutelins (93%). In the bioaccessibility assays, Fe was 83% bioaccessible in Fe-enriched sprouts.

Distribution of genetic variation in five coppice growth traits among natural populations of seven North American willow (Salix) species

Genetic variation and population structure in biomass yield and coppice growth traits were assessed in seven native North American willow species (Salix amygdaloides (AMY), Salix bebbiana (BEB), Salix discolor (DIS), Salix eriocephala (ERI), Salix humilis (HUM), Salix interior (INT), and Salix nigra (NIG)) established together in common-garden field tests on two sites. Differences in biomass yield, coppice stem number, and average single-stem mass were significant at the site, species, population, and genotype (clonal) levels. There were also species × site interactions. Analyses of variance components for these traits showed that only 3%–5% of the total variation in these traits was due to site differences, whereas genetic variation at the species, population, and genotype levels accounted for approximately 10%–39%, 5%–13%, and 12%–23%, respectively. Populations were a significant source of variation in some willow species (e.g., AMY, DIS, ERI, and INT) but not in other species. Tree willows were less prolific in stem sprout production than shrub willows, and ERI coppices produced by far the highest number of stem sprouts per coppice. This multispecies investigation demonstrated strong species and clonal differences, but variation among populations within a species, although significant, was relatively small, indicating that major growth and yield gains can be made through proper species selection and clonal selection within local populations.

Brotos de linhagens genéticas de soja: avaliação das propriedades físico-químicas

Resumo Brotos de soja são vegetais de consumo direto, obtidos de grãos germinados, que são utilizados há séculos nos países orientais. Suas características nutritivas e a facilidade de produção têm chamado a atenção de consumidores do Ocidente. Sementes pequenas com alto poder germinativo e vigor são qualidades inerentes para produção de brotos. Na Embrapa, essas características têm sido contempladas no programa de melhoramento genético para obtenção de cultivares de soja especiais para o consumo humano. O objetivo deste trabalho foi produzir e caracterizar a qualidade de brotos de soja obtidos a partir das linhagens BRM09-10505, BRM10-60599 e PF133002, em comparação com a cultivar BRS 216, desenvolvida para ser utilizada como brotos ou natto. Os brotos foram produzidos em bandejas dispostas em câmara de germinação (25°C e 99% de umidade relativa). Sementes e brotos foram avaliados nos seguintes aspectos: teor de proteínas, lipídios, cinzas, isoflavonas, inibidor de tripsina Kunitz, ácido fítico, comprimento e peso dos brotos. As sementes da BRM09-10505 apresentaram 95% de poder germinativo, seguida pela BRS 216 (93%) e pelas outras linhagens (88%, em média). A germinação pela mobilização dos compostos químicos aumentou os teores de proteínas (8,96%) e de isoflavonas (56,00%) e reduziu os teores de inibidor de tripsina Kunitz (26,91%) e de ácido fítico (13,78%). A cultivar BRS 216 apresentou o maior teor de proteína nas sementes (41,96 g.100 g-1) e nos brotos (47,70 g.100 g-1). A linhagem BRM09-10505 apresentou maior teor de inibidor de tripsina nas sementes (27,56 mg IT g-1) e nos brotos (19,62 mg. IT g-1); maior concentração de isoflavonas totais nas sementes (340,10 mg.100 g-1) e nos brotos (406,38 mg.100 g-1), e menor teor de ácido fítico nos brotos (1,13 g.100 g-1). Após quatro dias de germinação, destacaram-se, quanto ao comprimento e ao peso, a linhagem BRM09-10505 (8,03 cm e 214,36 g) e a cultivar BRS 216 (7,31 cm e 140,93 g). Entre as linhagens testadas, a linhagem BRM09-10505 apresentou bom potencial para produção de brotos.

A Simple Nano-SiO2-Based ELISA Method for Residue Detection of 2,4-Dichlorophenoxyacetic Acid in Bean Sprouts

The abusive use of 2,4-dichlorophenoxyacetic acid (2,4-D) was very common in the commercial production of bean sprouts. Herein, a simple and highly sensitive nano-SiO2-based ELISA method for residual 2,4-D detection was developed. The test depends on the direct competitive combination to anti-2,4-D antibody labeled by horseradish peroxidase (HRP) between nano-SiO2 immobilized by ovalbumin-2,4-D (SiO2-OVA-2,4-D) and free 2,4-D in sample. The linear range of this method was from 1 to 350 ng/mL (r = 0.997), and the limit of detection (LOD) was 0.079 ng/mL. The coefficient variations of intra-day and inter-day were all lower than 10% at three concentrations (20, 150, and 250 ng/mL). The mean recovery was 93.2%, and the specificity was satisfactory. The results indicated that the method could be useful for fast determination of residual 2,4-D in bean sprout samples using classic TMP/HRP system and a conventional UV spectrophotometer.

Growth and survival of reared Cambodian field crickets (Teleogryllus testaceus) fed weeds, agricultural and food industry by-products

This study evaluated survival and growth of Cambodian field crickets (Teleogryllus testaceus) during captivity when fed a set of local weed species, agricultural and food industry by-products. Wild individuals were caught at two locations in Cambodia, kept in pens and fed commercial chicken feed until the second generation off-spring hatched. First larval stage nymphs from this generation were collected and used in a 70-day feeding trial with one control treatment (chicken feed) and 12 experimental treatments (rice bran, cassava plant tops, water spinach, spent grain, residue from mungbean sprout production, and Alternanthera sessilis, Amaranthus spinosus, Commelina benghalensis, Cleome rutidosperma, Cleome viscosa, Boerhavia diffusa and Synedrela nodiflora). The crickets were kept in plastic cages and feed intake, weight and survival of crickets were recorded weekly. Overall survival did not differ between chicken feed and the experimental treatments with the exception of crickets fed B. diffusa, which had lower survival. From day 35 to day 49, survival on A. sessilis was also lower (P&lt;0.05) than on chicken feed. There was no difference in weight between crickets fed chicken feed, cassava tops and C. rutidosperma. However, crickets fed A. sessilis, A. spinosus and B. diffusa weighed less than those fed chicken feed already at day 21. The feed conversion rate ranged from 1.6 to 3.9 and was ≤1.9 in crickets fed chicken feed, cassava plant tops and C. rutidosperma. Thus this study shows that it is possible, using simple means, to rear Cambodian field crickets. Cassava plant tops and C. rutidosperma both have great potential as cricket feed and the other weeds, with the exception of A. sessilis, A. spinosus and B. diffusa, agricultural and food industry by-products tested, also showed potential.

Application of plant hydrosols for decontamination of wheat, lentil and mung bean seeds prior to sprouting

It is a requirement for both minimally processed and ready-to-eat fruit and vegetable industry and consumers to decrease use of harmful chemical antimicrobial agents such as chlorinated compounds in fresh product sanitation since they have a number of negative health and environmental effects. In this study, washing treatments with summer savoury, bayleaf and thyme hydrosols that are by-products essential oils were assessed for decontamination of wheat, mung bean and lentil seeds contaminated with Salmonella Typhimurium and Staphylococcus aureus prior to sprout production. Initial levels of S. aureus on wheat, lentil and mung bean were 4.86, 4.24 and 4.23 log colony forming units/g, respectively. Hydrosol treatments reduced S. aureus numbers significantly (P<0.05) depending on treatment time while the pathogen was not detected on mung bean soaked in the thyme hydrosol for 40 min. Sensitivity of S. Typhimurium was higher than S. aureus and thyme hydrosol achieved elimination of Salmonella on all of the see...

Plasma inactivation of microorganisms on sprout seeds in a dielectric barrier discharge

Fresh produce is frequently contaminated by microorganisms, which may lead to spoilage or even pose a threat to human health. In particular sprouts are considered to be among the most risky foods sold at retail since they are grown in an environment practically ideal for growth of bacteria and usually consumed raw. Because heat treatment has a detrimental effect on the germination abilities of sprout seeds, alternative treatment technologies need to be developed for microbial inactivation purposes. In this study, non-thermal plasma decontamination of sprout seeds is evaluated as a promising option to enhance food safety while maintaining the seed germination capabilities. In detail, investigations focus on understanding the efficiency of non-thermal plasma inactivation of microorganisms as influenced by the type of microbial contamination, substrate surface properties and moisture content, as well as variations in the power input to the plasma device. To evaluate the impact of these parameters, we studied the reduction of native microbiota or artificially applied E. coli on alfalfa, onion, radish and cress seeds exposed to non-thermal plasma in an atmospheric pressure pulsed dielectric barrier discharge streamed with argon. Plasma treatment resulted in a maximum reduction of 3.4 logarithmic units for E. coli on cress seeds. A major challenge in plasma decontamination of granular food products turned out to be the complex surface topology, where the rough surface with cracks and crevices can shield microorganisms from plasma-generated reactive species, thus reducing the treatment efficiency. However, improvement of the inactivation efficiency was possible by optimizing substrate characteristics such as the moisture level and by tuning the power supply settings (voltage, frequency) to increase the production of reactive species. While the germination ability of alfalfa seeds was considerably decreased by harsh plasma treatment, enhanced germination was observed under mild conditions. In conclusion, the results from this study indicate that cold plasma treatment represents a promising technology for inactivation of bacteria on seeds used for sprout production while preserving their germination properties.