Trend Toward Consuming Raw Vegetables: Is There a Need to Reassess Testing Protocols?

Consumers are becoming more health conscious and are including more fruits and vegetables in their diets. The growing trend toward the consumption of raw vegetables is due to the consumer belief that uncooked produce has higher levels of nutrients. The nutritional science is mixed on this question, with evidence that some nutrients are reduced after cooking, such as vitamin C, while other nutrients are more accessible, because cooking breaks down the vegetable’s cell walls. As a result of this dietary trend, some vegetables that would have historically been cooked, such as brussel sprouts, are now being eaten raw. This change in consumption raises new risks that laboratory protocols must adapt to in order to protect consumer health and prevent product recalls.

Much like raw milk, fresh produce is a high-risk item for pathogens and must be carefully monitored through testing protocols. For example, Skočková et al. (1) analyzed raw vegetables for the presence of E. coli and found high levels among sprouted seeds (53.3%) and lettuce samples (38.9%). Other samples with positive results for E. coli were cucumber, spring onion, cauliflower and asparagus. According to the Centers for Disease Control, between 1998 and 2007, fresh produce accounted for a greater incidence of foodborne illness (684 outbreaks) than animal products such as poultry (538), beef (428) and pork (200). Considering the 2011 outbreak of Shiga Toxin-producing Escherichia coli O104:H4 in German alfalfa sprouts, it is clear that foodborne pathogens in fresh produce can be deadly.

The CDC highlights E. coli, Listeria and Salmonella as the three most common causes of food poisoning from raw fruits and vegetables. These risk assessments are based on traditional levels of raw or cooked consumption. However, as habits change, it is important to consider the mode of consumption. These new trends move some vegetables that would have previously been consumed cooked into a high-risk category, where they require further monitoring.

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Reference:

1. Skočková, A., KarpíškoO157:H7 vá, R., Koláčková, I., and Cupáková, Š. (2013) “Characteristics of Escherichia coli from raw vegetables at a retail market in the Czech Republic.” International Journal of Food Microbiology 167, 196–201.

Post Author: Heather van der Hoop.