A worldwide review of illness outbreaks involving mixed salads/dressings and factors influencing product safety and shelf life

• Published in: Food microbiology Vol. 112; p. 104238
• Main Authors: Osaili, Tareq M., Hasan, Fayeza, Al-Nabulsi, Anas A., Olaimat, Amin N., Ayyash, Mutamed, Obaid, Reyad S., Holley, Richard
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2023
• Subjects: Antimicrobial treatment; Disease Outbreaks; Food Microbiology; Food safety; Foodborne Diseases - prevention & control; Foodborne illness outbreaks; Humans; Hygiene; Multicultural diets; Produce shelf life; Salads; Vegetables; Food safety; Multicultural diets; Antimicrobial treatment; Foodborne illness outbreaks; Produce shelf life
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2023.104238

The trends toward healthy living, vegetarianism, and busy schedules have increased salad popularity. Salads are usually consumed raw without any thermal treatment, and therefore, without proper care they can become major vehicles for foodborne illness outbreaks. This review examines the microbial quality of ‘dressed’ salads which contain two or more vegetables/fruits and salad dressings. The possible sources of ingredient contamination, recorded illnesses/outbreaks, and overall microbial quality observed worldwide, besides the antimicrobial treatments available are discussed in detail. Noroviruses were most frequently implicated in outbreaks. Salad dressings usually play a positive role in influencing microbial quality. However, this depends on several factors like the type of contaminating microorganism, storage temperature, dressing pH and ingredients, plus the type of salad vegetable. Very limited literature exists on antimicrobial treatments that can be used successfully with salad dressings and ‘dressed’ salads. The challenge with antimicrobial treatments is to find ones sufficiently broad in spectrum, compatible with produce flavour which can be applied at competitive cost. It is evident that renewed emphasis on prevention of produce contamination at the producer, processor, wholesale and retail levels plus enhanced hygiene vigilance at foodservice will have a major impact on reducing the risk of foodborne illnesses from salads. •Evidence suggests that some salad dressings may have antimicrobial action.•Antimicrobial action in salads could be of physical, chemical or biological nature.•A great gap exists in the literature about antimicrobial strategies in dressed salads.•A farm to fork approach is needed to reduce microbial numbers in salads.