Diana Jasso de Rodríguez

Perspectives on Utilization of Edible Coatings and Nano-laminate Coatings for Extension of Postharvest Storage of Fruits and Vegetables

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.

Productivity and cytogenetic characteristics of guayule. Screening of plants from the mapimi region

Guayule plants were screened in the region of Mapimi (Durango, Mexico) to evaluate physicochemical parameters for selection of increased productivity. The objective was to characterize rubber, and resin content, stem diameter, rubber molecular weight and cytology of these plants to identify and select high productivity sites. Samples were collected from nine locations within the Mapimi Region. Inflorescences containing young floral buds of the same plants were selected to determine ploidy level. Cytogenetic results showed the presence of di-, tri- and tetraploids. Samples for rubber and resin analysis were cut from the branches. Genetic variation in molecular weight and molecular weight distributions for rubber was measured. Significant differences were found in resin content and stem diameter between the sampling sites, but differences were not significant for the rubber content between sites. A productivity parameter was defined and used to identify two locations where guayule genotypes exhibited the best characteristics for commercialization. This information may increase the industrial development and understanding of the polymerization bioprocess.

Comparison of Soxhlet and homogenizer extraction methods to determine rubber and resin content of Mexican guayule plants

Abstract A comparison was made between the Soxhlet analysis (SA) and homogenizer extraction method (HEM) in determining the rubber and resin content in the root, main stem, and branch tissues of 10 genotypes of guayule grown in Mexico. The analysis of variance indicated significant differences in percentage of rubber and resin between genotypes, and individually in the root, stem, and branch tissues, and also between two rubber extraction procedures. The average rubber in the root, stem, and branches as determined by the SA was 2·48, 4·14, and 4·66%, respectively; in the HEM, comparable figures were 2·62, 3·48, and 3·84%, respectively. The SA estimated 18·97% and 20·83% higher rubber content in the stem and branches tissues over HEM. The SA method yielded higher percentage values for rubber and resin contents when compared to the HEM. The HEM requires considerably less time to analyze the samples.

Flourensia cernua DC: A Plant from Mexican Semiarid Regions with a Broad

Mexico has an extensive variety of plants, it is the world ́s fourth richest country in this aspect. Some 25,000 species are registered, and it is thought that there are approximately 30, 000 not described. Particularly the regions of the north of Mexico, with their semiarid climate, have a great number and variety of wild plants grown under extreme climatic conditions. Wild species which have compounds with flavonoid structures, sesquiterpenoids, acetylenes, p-acetophenones, benzofurans, and benzopyrans grow in these regions. The polyphenolic compounds include tannins and flavonoids which have therapeutic uses due to their anti-inflammatory, antifungal, antibacterial, antioxidant, and healing properties.

Scale-up and evaluation of hydrothermal pretreatment in isothermal and non-isothermal regimen for bioethanol production using Agave bagasse

The production of tequila in Mexico generates a large amount of agave bagasse per year. However, this biomass can be considered as a potential source for biofuel production. In this study, it is described how the hydrothermal pretreatment was scaled in a bench scale, considering the severity index as a strategy. The best condition was at 180 °C in isothermal regime for 20 min with 65.87% of cellulose content and high concentration of xylooligosaccharides (15.31 g/L). This condition was scaled up (using severity factor: [logR0] = 4.11), in order to obtain a rich pretreated solid in cellulose to perform the enzymatic hydrolysis, obtaining saccharification yields of 98.5 and 99.5% at high-solids loading (10 and 15%, respectively). The pre-saccharification and fermentation strategy was used in the bioethanol production at 10 and 15% of total pretreated solids, obtaining 38.39 and 55.02 g/L of ethanol concentration, corresponding to 90.84% and 87.56% of ethanol yield, respectively.

Variability for seedling growth characters and correlations in guayule

Abstract Twenty-four genotypes of guayule were evaluated in the greenhouse at 12 (D1) and 60 days (D2) from seeding. The analysis of variance indicated a considerable variability in principal root length at D1 and D2 and for number of roots and seedling height at D2 only. The accession numbers 4207, 4168, 4243, and 4122 recorded values that were higher than the mean for all the seedling traits. Seedling height was positively and significantly correlated with number of roots and number of leaves per seedling in D2.