Microplastics in Food: A Review on Analytical Methods and Challenges

Abstract

Human exposure to microplastics contained in food has become a significant concern owing to the increasing accumulation of microplastics in the environment. In this paper, we summarize the presence of microplastics in food and the analytical methods used for isolation and identification of microplastics. Although a large number of studies on seafood such as fish and shellfish exist, estimating the overall human exposure to microplastics via food consumption is difficult owing to the lack of studies on other food items. Analytical methods still need to be optimized for appropriate recovery of microplastics in various food matrices, rendering a quantitative comparison of different studies challenging. In addition, microplastics could be added or removed from ingredients during processing or cooking. Thus, research on processed food is crucial to estimate the contribution of food to overall human microplastic consumption and to mitigate this exposure in the future.

Marine Microplastics and Seafood: Implications for Food Security

“…While the focus of the scientific literature has primarily been on human exposure to microplastics from seafood consumption, much less data is available on the occurrence of microplastics in other food groups, so their relative contribution is unknown which is important from a risk assessment perspective (Wright and Kelly 2017). Data on microplastics in foods (Kwon et al 2020) other than seafood include sugar, salt, honey, and drinking water and beer (Karbalaei et al 2018), whereas there are significant data gaps for plant-and terrestrial animal-derived foods (van Raamsdonk et al 2020). To date there are also limited data on microplastic levels in freshwater fish (Collard et al 2019) and terrestrial foods (e.g., vegetables, poultry).…”

Microplastic in Food and Drinking Water - Environmental Monitoring Data

“…It is, therefore, possible that the amount of microplastics increases during processing. The effect of other processes, e.g., cooking and baking, on the content of plastics is not known [6,17]. Limited data are available on the occurrence of microplastics in foods.…”

“…Plastic particles were detected in 5.5% of the fish examined, with 74% of all particles being in the microplastic (< 5mm) size range (1-7 particles/fish) and almost 40% of the particles consisted of PE. Kwon et al [6] summarized the presence of microplastics in food based on literature data from 2019 in 1800 articles (Fig. 1).…”

Development of Optimal Digesting Conditions for Microplastic Analysis in Dried Seaweed Gracilaria fisheri

“…To isolate MPs from marine animals, previous research applied different digestion methods including acid [ 8 , 22 ], alkaline [ 23 ], oxidative [ 11 , 23 , 24 , 25 ], enzymatic [ 23 , 26 , 27 , 28 ], and a combination of several methods, such as a stepwise method using sodium hydroxide (NaOH) and nitric acid (HNO 3 ) [ 29 ]. Meanwhile, the extraction of MPs from vegetal tissues, namely nori seaweed, broccoli, lettuce, carrot, and potato, is limited to using 65% HNO 3 [ 30 ] and a more extensive digestion method using a combination of cellulase, protease, and 30% hydrogen peroxide (H 2 O 2 ) [ 31 ].…”

“…Environmental stressors such as UV radiation, elevated temperature, oxidation, and water abrasion degrade this waste into small-sized plastic particles (smaller than 5 mm), so-called microplastics (MPs) [2][3][4]. The abundance of MPs in terrestrial [5] and aquatic [6] ecosystems and the findings of MP contamination on various food products [7,8] have aroused global concern about MP accumulation in the food web.…”