This study investigated potential contamination sources in a commercial, closed hydroponic system. Water, substrate and lettuce (Lactuca sativa) samples were evaluated for microbiological indicator populations, including aerobic plate count (APC), coliform bacteria (CB) and yeast and mould (YM). Listeria spp. detection via cultural enrichment and agglutination was negative for all samples. Peat moss substrate (postharvest) had the highest counts for APC (6·8 log CFU per g), CB (4·5 log MPN per g) and YM (5·1 and 4·8 log CFU per g respectively). Roots embedded in plugs demonstrated counts for all populations nearly as high as the substrate. Among water samples, a seedling water reservoir housing germinated plants yielded the highest count for APC (5·1 log CFU per g) and CB (2·4 log MPN per g) likely due to the large numbers of plugs and their close proximity in the reservoir. Harvested lettuce leaves demonstrated higher APC (4·1 log CFU per g) than preharvest leaves (1·7 log CFU per g) due to the transfer of microbes from the root ball. These data suggest that substrates are a significant potential source of contamination in hydroponic systems and likely facilitate microbial transfer to harvested leaves. There is, therefore, the need to further investigate mitigation of potential contamination events. Significance and Impact of the Study Hydroponic production is known to provide safe, clean produce. This study, however, suggests that the hydroponic substrate (peat moss plug) is a possible source of contamination in the hydroponic system. This finding is important as most harvested hydroponic lettuces are packaged and sold with substrate and root ball intact. This implies a high probability of microbial transfer from the root ball to edible harvested lettuce leaves.

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BACKGROUND Most hydroponic lettuce growers harvest and package their marketable‐size lettuces with an intact root ball. With a high microbial load on the peat moss substrate, there is a risk of microbial transfer onto the edible portion during packaging and throughout the product's shelf life. Since the produce is believed to have no contact with the substrate, no sanitizer wash is performed before packaging and storage. RESULTS Aerobic plate count (APC) results suggested that reduction in count was influenced by both sanitizer application and storage time. Peroxyacetic acid significantly reduced APC count on leaves, roots, and substrate, with a 1.8 log CFU g−1 initial reduction on the leaf. Fungi and APC levels increased with storage time, with the greatest APC increase in the roots. Leaves had the lowest coliform bacteria (CB), with chlorine slightly reducing CB count. Unlike APC, CB levels decreased during storage on the substrate and root samples. No Listeria positive was confirmed by agglutination test. Further evaluation of different commercial substrates reveals that Com4, a drier‐compacted plug, had the least ability to support growth/survival of all microbial populations enumerated relative to the spongy, wet black plugs. CONCLUSION The ability of peat moss substrates to host microorganisms is influenced by the physical properties of the product. Sanitizer wash efficacy is dependent on the initial microbial load and the length of storage. Chlorine and peroxyacetic acid are effective in reducing microbial populations on the leaves of hydroponically grown lettuce without affecting visual quality during shelf life. © 2020 Society of Chemical Industry

Entomophagy has been touted as one of the solutions for present and likely upcoming food shortages, especially of protein-rich foods, due to the current pace of global population growth. "Minilivestock" require less water, space, and other resources compared to traditional livestock, which makes it an environmentally conscious option. Nonetheless, the Western world lags behind in the consumption of insects, and research and standardization of industrial practices are lacking. One of the most easily accessible insect-based foods in the United States is powdered cricket, which can be used as an adjunct to or substitute for traditional flours. We purchased two lots of eight brands of cricket powders and assessed their food quality and protein and fat composition. Counts of aerobic mesophiles, coliforms, Staphylococcus, fungi, Bacillus, presumptive Bacillus cereus, and aerobic and anaerobic spores varied greatly among brands as well as batches for the same brand. Protein and fat composition were similar on a g/100 g basis among brands, but the labeled serving sizes varied from 10 to 36 g, which made nutrition facts labels vary considerably. Standardization in multiple aspects, including demonstrated food safety, is paramount for the future of the industry.

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ResumoGarapa e extrato de levedura foram usados na produção de asparaginase por Zymomonas mobilis CP4. Na otimização utilizou metodologia de superfície de resposta com 2 variáveis (extrato de levedura e asparagina) em 3 níveis (1,0; 5,5 e 10,0 g/L) e uma repetição do ponto central. A fermentação em batelada utilizou garapa diluída a 8 % (P/V) de Açúcares Totais e inóculo de Zymomonas mobilis CP4 na concentração de 2 mg/mL. Após a fermentação de 18 horas, a maior produção obtida de asparaginase foi de 9,75 U/L em extrato de levedura em 5,5 g/L e asparagina em 1,0 g/L. Palavras-chave: Garapa, Zymomonas mobilis, asparaginase, fermentação AbstractSugar cane juice and yeast extract have been used for asparaginase production by Z. mobilis CP4. A complete factorial design of two variables (yeast extract and asparagin) at three levels (1.0; 5.5 and 10.0 g/L) with one replication at the central point was used. Batch fermentation utilised sugar cane juice diluted at 8 % (W/V) of Total Sugars and an inoculum of 2 mg of cells/mL. After fermentation time of 18 hours, the highest production of asparaginase was 9.75 U/L using both yeast extract (5.5 g/L) and asparagin (1.0 g/l).

Traditional use of direct observation (DO) includes written records or audiovisual devices. These overt methods can cause artificial behavior change due to being observed (Hawthorne Effect (HE)) and results can be biased and less valid. A recent tool developed to perform DO is a smartphone application (PA) which allows researchers to collect data without intrusion while decreasing HE bias. A PA can be used to collect food safety behavior data to determine actual practices and which best practices need reinforcement. As consumers want fresh local produce, farmers markets (FM) are more popular and numbers have increased nationally. Using a PA for DO of food safety behaviors at FM can provide an accurate assessment of food safety handling practices by produce vendors. A PA was developed to assess food safety behaviors at FM during the summer of 2013. Assessment questions were developed, reviewed, entered online and uploaded in the PA technology. Twenty‐six produce vendors were observed at 14 FM for a mean of 18.3 ± 5.8 minutes. Six markets had <4 and 8 had 蠅4 vendors. The 5 most observed products were tomatoes, zucchini, cucumbers, peppers, and lettuce. Common observed practices that impact produce food safety included eating, talking on the phone, and touching money and then touching produce. Future research using PA could determine gaps in behaviors that will be used in the development of food safety training for FM vendors. Grant Funding Source: Supported by URI/AES, Regional Project S‐1056