Study reveals contamination risks and solutions in ready-to-eat salads

In a analysis paper revealed within the journal Developments in Meals Science & Know-how, the authors have highlighted the crucial factors in packaged salad manufacturing processes that is perhaps related to the origin of microbial contamination.

They’ve additionally mentioned the options accessible to make sure sufficient microbiological high quality management and well being and security.

Examine: From farm to fork: Fungal and bacterial contaminants and their diagnostics within the manufacturing steps of ready-to-eat salads. Picture Credit score: monticello / Shutterstock

Background

Prepared-to-eat inexperienced leafy greens or ready-to-eat salads characterize a really fast-growing market. These merchandise are marketed already washed in sealed luggage and are supposed to be consumed uncooked, with out cooking.

The ready-to-eat nature of those merchandise highlights the necessity for stringent and complete microbiological high quality management to make sure well being and security. Numerous strategies and situations related to vegetable cultivation, washing, bagging, storage, transport, and distribution are the foremost determinants of product high quality.

Prepared-to-eat salads could comprise numerous pathogens, together with micro organism, yeast, and filamentous fungi, which might scale back the shelf-life of merchandise and impose human well being dangers. Harmful pathogens (parasites and viruses) related to foodborne illness outbreaks or contaminations have additionally been recognized in these meals merchandise.      

Dangers of microbial contamination

Employees coaching and hygiene are obligatory elements for meals security in ready-to-eat meals manufacturing programs. A number of sources, together with soil, amendments, manure-based fertilizers, water, neighboring poultry or livestock farms, and wildlife residues, can probably contribute to microbial contamination at pre- and post-harvest phases.

Water high quality is taken into account to be essentially the most crucial issue for microbiological security. The latest European Fee Regulation has suggested utilizing recycled water for irrigation. Water-based nutrient options for rising crops are anticipated to supply higher microbiological security than standard soil-based programs as they function in a managed surroundings, keep away from animal manure and soil-borne illnesses, and decrease plant contamination with human pathogens.

Nevertheless, recycled water and nutrient options, seeds, seedlings, and substrates have been recognized as additional sources of microbial contamination in soilless plantation applied sciences. This means that water in recirculating programs can catch contamination extra quickly than standard soil-based cultivation.  

In line with the Meals Code of the U.S. Meals and Drug Administration (FDA), ready-to-eat salads are probably hazardous meals merchandise, as they have been related to a number of outbreaks between 1998 and 2008.

The microbiological standards established by the European Fee Regulation for accepting ready-to-eat merchandise are primarily based on the presence, absence, or variety of microbes and the focus of poisons or dangerous metabolites. The meals security standards are the absence of L. monocytogenes and Salmonella spp. in 25 grams of non-expired merchandise.

The primary threat elements in ready-to-eat meals manufacturing are transport, processing, and storage temperature, water high quality and sanitation, gear design, hygiene situations, and employee private hygiene and coaching.

Potential hazards can also come up on the crucial management factors alongside the manufacturing course of, together with reception of uncooked supplies (assortment and storage), choice (guide cleansing and reducing), disinfection (washing and drying), packaging (luggage, packing containers, wrapping), and distribution (native storage, transport to market).

Sustaining a low ambient temperature through the manufacturing and storage of meals merchandise is important for lowering pathogen development charges. Nevertheless, it isn’t ample to fully forestall pathogen development.

The usage of disinfectants to take care of water high quality is crucial, as water and product contamination and cross-contamination with enteric pathogens can happen throughout washing. Chlorine is essentially the most extensively used disinfectant due to its excessive effectiveness and low worth. Different disinfectants are ozone, electrolyzed water, acidified sodium chlorite, hydrogen peroxide, natural acids, bromine, and iodine.   

Gear, reducing machines and instruments, biofilm formation, and conveyor belts are essentially the most vital contamination hotspots. Throughout product packaging, it’s vital to find out the right mixture of movies, product weight, and gasoline composition to make sure product high quality, security, and shelf life.   

Correct labeling of ready-to-eat meals merchandise with info on substances, dietary worth, and origin is essential for making certain transparency for customers. Labels also needs to embrace info on storage temperature, expiry date, and product supply.

Microbiological strategies for screening ready-to-eat salads

A number of microbiological strategies have been developed for detecting pathogenic microbes in ready-to-eat meals merchandise, together with salads. A number of major agar media can be found that can be utilized to detect microbes in these merchandise.

Microbial colonies remoted from agar plates are characterised by biochemical and serological exams to establish major human pathogens, together with Escherichia coli, Staphylococcus aureus, Salmonella enterica, and Listeria monocytogenes.

Molecular strategies, reminiscent of polymerase chain response (PCR)-based assays, are additionally used for colony identification affirmation or for focused identification of particular pathogens in enrichment media.

The appliance of high-throughput screening strategies is rising in meals security, focusing on culturable and non-culturable pathogens and spoiling brokers in ready-to-eat salads. Some novel strategies, together with shotgun metagenomics and metatranscriptomics, are gaining recognition as a result of they will instantly sequence the goal nucleic acids to supply obligatory microbial info.   

The present focus of meals industries is on sustainable, low-cost, type-specific new applied sciences that may profit the manufacturing chain of ready-to-eat salads. Some novel strategies have been developed to qualitatively and quantitatively assess microbial dangers by monitoring crucial manufacturing factors in real-time.

Nanopore-based DNA sequencing applied sciences coupled with bioinformatics evaluation pipelines work by feeding specifically educated prediction fashions and multivariate analyses for the early detection of microbiological contamination.

Conclusion

Whereas zeroing microbiological threat in ready-to-eat salads is statistically unrealistic because of the potential for contamination all through the manufacturing chain, developments in sustainable applied sciences and rigorous microbiological high quality management can considerably mitigate these dangers and improve meals security earlier than salads attain customers.