# Sustainability in Bio-Based Edible Films, Coatings, and Packaging for Small Fruits
## 5 Edible Film and Coating Functionalities Important for the Small Fruit Industry
### Bioactivity of the Edible Films and Coatings
#### 5.1.4 Anti-Cracking  
Edible films and coatings offer several essential functionalities for the small fruits industry, particularly their bioactivity [84; 174]. Another crucial aspect is their ability to prevent cracking, a significant concern for many small fruit varieties. Indeed, small fruits, such as cherries, grapes, and berries, are highly susceptible to cracking, which can significantly reduce their market value and shelf life [175]. Cracking occurs when the fruit rapidly uptakes water due to rainfall or high humidity, causing the fruit skin to split [175]. Edible films and coatings can mitigate this issue through various mechanisms: (i) moisture barrier, which creates a semi-permeable barrier on the fruit surface, regulating moisture transfer between the fruit and its environment [176]. This barrier helps prevent excessive water uptake during periods of high humidity or rainfall, reducing the internal pressure that leads to cracking. Polysaccharide-based coatings, such as those made from alginate or pectin, have shown particular promise in this regard due to their ability to form cohesive films [42]; (ii) structural reinforcement, as some edible coatings can enhance the mechanical strength of the fruit skin. For instance, protein-based coatings derived from whey or soy proteins can form a flexible yet strong layer that reinforces the fruit's natural protective barrier [43]. This added strength helps the fruit withstand the internal pressure caused by water uptake, thus reducing the likelihood of cracking; (iii) elasticity enhancement, as specific coating formulations can improve the elasticity of the fruit skin, allowing it to expand without breaking when the fruit absorbs water. Lipid-based coatings, often used in combination with hydrocolloids, can contribute to this effect by providing flexibility to the coating layer [176]; (iv) controlled ripening, by modifying the internal atmosphere of the fruit, edible coatings can slow down the ripening process. This is particularly beneficial for cracking prevention, as overripe fruits are more susceptible to splitting. Coatings that create a modified atmosphere with reduced oxygen permeability can delay ripening and maintain fruit firmness [2]; (v) integration of active compounds, as edible coatings, can be enriched with various bioactive compounds contributing to cracking prevention. For example, incorporating calcium salts into the coating formulation can enhance the structural integrity of the fruit cell walls, making them more resistant to cracking [177; 178]. Similarly, adding antioxidants can help maintain the elasticity of the fruit skin by preventing oxidative damage [42; 179]. Research has demonstrated the effectiveness of anti-cracking edible coatings on various small fruits. For instance, a study on sweet cherries showed that a chitosan-based coating significantly reduced cracking incidence compared to uncoated fruits [47]. Similarly, alginate coatings have been found to reduce water uptake and cracking in grapes while also maintaining their overall quality during storage [180; 181]. In conclusion, the anti-cracking functionality of edible films and coatings represents a valuable tool for the small fruits industry. By providing a protective barrier, enhancing structural integrity, and allowing for the incorporation of beneficial compounds, these coatings can significantly reduce fruit losses due to cracking. Indeed, cracking can occur due to physiological, genetic, or environmental factors. The combination of those factors makes fruit cracking challenging to study, even in controlled conditions, and the basic mechanisms involved remain unclear [174]. As research in this field advances, we can expect even more effective and tailored solutions for specific fruit varieties and environmental conditions, further improving the quality and marketability of small fruits.