Antifungal edible coatings for fruits based on zein and chitosan nanowhiskers

Fresh produce have a more limited shelf life than processed ones. Their sensory attributes such as appearance and surface texture are important features in consumer perception and liking. The decomposition of fresh produce, which is caused by enzymes, chemical reactions, and microbial infections, often caused by Colletotrichum species, is inevitable. However, it can be slowed down. Several materials have been developed for this purpose, with an emphasis on active coatings using nanomaterials. In this study, the protective effects of a zein coating containing chitosan nanowhiskers (CSW) for the maintenance of fruit quality were investigated using guava (Psidium guajava L.) as a model fruit. CSW were previously characterized, and their antifungal effects against distinct Colletotrichum species (Colletotrichum asianum, Colletotrichum tropicale, Colletotrichum gloeosporioides, and Colletotrichum brevisporum) were proven. Coatings were characterized by thermogravimetric analysis, optical profilometry, and mechanical properties. Total soluble solids, pH, mass loss, and visual inspection of uncoated and coated guava fruits were also verified during 9 days. Results show that CSW length and aspect ratio decreased for longer extraction times. A similar behavior was found for x-ray diffraction in which peak intensity decreases under the same conditions. CSW degradation (ca. 250-400°C) also depends on extraction time in which more crystalline whiskers are the most thermally stable ones. The addition of CSW did not significantly (p < 0.05) modify the homogeneity and continuity of coating but prevented microbial growth assuring fruit quality during storage. In summary, coatings protected guava fruits from post-harvest spoilage while preserving quality and extending shelf life. PRACTICAL APPLICATION: Fresh foods such as fruits and vegetables have a more limited shelf life than processed ones.

Impact of animal origin of milk, processing technology, type of product, and price on the Boursin cheese choice process: Insights of a discrete choice experiment and eye tracking

Boursin is a versatile semisoft cheese that can be made with different types of milk. While widely distributed in the European and North American markets, Boursin is produced to a limited extent in Brazil despite its commercial potential. This scenario encourages consumer-oriented product development studies by facilitating data collection with less bias and fewer product preconceptions, thus favoring the investigation of technological aspects of commercial interest. This study evaluates Brazilians' perceptions regarding different versions of Boursin cheese, with the aim of gaining a better understanding of the factors related to choosing cheese. Four attributes related to cheese production were evaluated at three different levels using two discrete choice experiments: one with eye tracking (n = 20) and another without (n = 312). These attributes included "type of processing" (evaluating pasteurization, ohmic heating, and preparation with raw milk), "animal origin of milk" (cow, goat, or buffalo milk), "type of product" (traditional, light, and lactose-free versions), and "price" (10.99, 13.99, and 16.99 BRL). Information regarding processing with ohmic heating did not affect the probability of Boursin being chosen, suggesting that consumers are open to using this emerging technology in Boursin cheese. However, information on being made with goat, buffalo, and raw milk negatively impacted the probability of choice, along with the price of 16.99 BRL. The frequency of cheese consumption and the level of health concerns also affected the probability of choosing the product. PRACTICAL APPLICATION: Identifying the relationship between extrinsic attributes presented on the Boursin cheese label and the consumer's choice process can aid the communication process with the target audience and reveal how some technological issues of interest to manufacturers are perceived. This study indicates how information regarding the animal origin of the milk (cow, goat, and buffalo), the type of processing (pasteurization, ohmic heating, and raw milk), the version of the product (traditional, light, and lactose-free), and the price affect the consumer choice process. The results provide insights that can be applied to product processing and designing labels.