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In the last decade, the use of multivariate statistical techniques developed for analytical chemistry has been adopted widely in food science and technology. Usually, chemometrics is applied when there is a large and complex dataset, in terms of sample numbers, types, and responses. The results are used for authentication of geographical origin, farming systems, or even to trace adulteration of high value-added commodities. In this article, we provide an extensive practical and pragmatic overview on the use of the main chemometrics tools in food science studies, focusing on the effects of process variables on chemical composition and on the authentication of foods based on chemical markers. Pattern recognition methods, such as principal component analysis and cluster analysis, have been used to associate the level of bioactive components with in vitro functional properties, although supervised multivariate statistical methods have been used for authentication purposes. Overall, chemometrics is a useful aid when extensive, multiple, and complex real-life problems need to be addressed in a multifactorial and holistic context. Undoubtedly, chemometrics should be used by governmental bodies and industries that need to monitor the quality of foods, raw materials, and processes when high-dimensional data are available. We have focused on practical examples and listed the pros and cons of the most used chemometric tools to help the user choose the most appropriate statistical approach for analysis of complex and multivariate data.

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There is a great interest in increasing the levels of production of nanocellulose, either by adjusting production systems or by improving the raw material. Despite all the advantages and applications, nanocellulose still has a high cost compared to common fibers and to reverse this scenario the development of new, cheaper, and more efficient means of production is required. The market trend is to have an increase in the mass production of nanocellulose; there is a great expectation of world trade. In this sense, research in this sector is on the rise, because once the cost is not an obstacle to production, this material will have more and more market. Production of the cellulose fibers is determinant for the production of nanocellulose by a hydrolyzing agent with a reasonable yield. This work presents several aspects of this new material, mainly addressing the enzymatic pathway, presenting the hydrolysis conditions such as pH, biomass concentration, enzymatic loading, temperature, and time. Also, the commonly used characterization methods are presented, as well as aspects of the nanocellulose production market.

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Passion fruit mesocarp flour (MF) is a material of low-cost, because it can be produced from industrial processing of juices. The aim of this study was to develop flexible films based on MF, and to characterize their barrier, chemical, microscopic, thermal and mechanical properties, as well as to evaluate the rheological properties of the filmogenic solution used to produce them. The use of clay nanoparticles (NP) was also investigated. Films from MF were prepared by casting method, with glycerol as a plasticizer. The film forming solution of MF was more viscous than solutions of starch. The results of the contact angle values showed that films made from MF are more hydrophilic compared to starch, but there was no significant difference in water vapor permeability (WVP) and the thickness between these two different matrices. Regarding mechanical properties, the films made from MF proved to be tougher, stronger and less flexible. The formulation based on a mixture of MF and starch resulted in films less rigid and less resistant to tension, as compared to films based only on MF. The addition of NP did not influence the barrier properties, thermal and mechanical properties of films. Therefore, preparing films from MF, a cheap material, is a new alternative for taking waste from juice industries.