# Exploring the Potential of Microextraction in the Survey of Food Fruits and Vegetable Safety
## 1 Introduction
### Food Safety--Major Contaminants of Fresh Fruits and Vegetables and Their Toxicity
#### 1.1.3 Food Preservatives  
Food and food products are susceptible to deterioration due to microbiological, enzymatic, physical, and chemical changes. These changes may reduce their quality, nutritional value, and safety [33]. To mitigate these deleterious effects, food additives are added to foodstuffs to perform specific functions, such as preserving food, adding colour, taste, sweetening, and texture, among others. Additives are added during the food's manufacture and their amount is determined for each foodstuff. To ensure that the overall daily consumption by an individual does not exceed the Admissible Daily Intake (ADI) [11; 33]. Preservatives are one of the most important groups of additives [33] and are subdivided into three smaller functional groups, which are antioxidants, antimicrobials, and antibrowning agents (Figure 1) [11]. Antioxidants prevent or inhibit lipid oxidation in food and the autoxidation of pigments, flavours, lipids, and vitamins [34]. They are classified as natural or synthetic and both have been reported to delay and prevent the cell damage caused by oxidative stress. The functional antioxidant groups of additives approved by EFSA have been reviewed by [PERSON] et al. [11]. Synthetic antioxidants are created from chemical processes [35]. Examples of synthetic antioxidants include terbutylhydroxyanisol (BHA, E320), butylhydroxytoluene (BHT, E221), tert-butylhydroquinone (TBHQ, E319), and propyl gallate (PG, E310) [11; 35; 36]. However, these have been associated with harmful health effects. BHA and BHT have shown carcinogenic and toxicological effects. TBHQ induces toxicity at cellular and molecular levels through reactive oxygen species (ROS) [36; 37], which results in detrimental impacts on deoxyribonucle acid (DNA) and some types of genotoxicity [38]. Concerning PG, it has been reported to contribute to mitochondrial impairment and inhibition of cellular respiration [39] as well as affect both cancer and normal cells, potentially leading to DNA fragmentation, genotoxicity, and cytotoxicity [36; 40]. Given the harmful health effects of synthetic antioxidants, there is a demand for new and more efficient natural antioxidant agents. Natural antioxidants are obtained entirely from natural sources and consumers believe in their safety and non-toxic impacts on health. Moreover, it has been demonstrated that natural non-enzymatic antioxidants can be beneficial in preventing a range of chronic diseases, such as cancer, diabetes, and cardiovascular diseases [33]. These compounds are natural food antioxidants and include polyphenols, phenolic acids, and carotenoids [11]. Antimicrobials are added to control and prevent natural spoilage and contamination by microorganisms [11; 34]. These compounds delay the proliferation and growth of pathogenic microorganisms (bacteria, yeasts, and moulds), ensuring food safety and quality [41; 42]. Generally, two types of antimicrobials are applied: natural and artificial types [33]. Artificial antimicrobials are substances of chemical origin, including salts and organic acids (e.g., propionates, benzoates, sulfites, nitrites, chlorides, potassium sorbate, lactate, sorbic, citric, tartaric, and ascorbic acids). However, some of these substances are still subject to discussion and have acknowledged controversy due to research inconsistency. For instance, sorbates, sulfites, and nitrates have been associated with cancer and allergies. Sulfites can induce deterioration of thiamine (vitamin B1) in foodstuffs [43] and their use can lead to allergic reactions (e.g., nausea, urtic, or asthma) in consumers with hypersensitivity to this compound [33]. Therefore, there is an increased interest in antimicrobials of natural origin. Plant extracts can be used as natural antimicrobials and they can protect fresh food while providing health benefits. Antimicrobial compounds in plants include essential oils, polyphenic compounds, polypeptides, lectins, and alkaloids, along with polyamines, organic acids, glucosides, and glucosinolates.