Elsa Bosquez-Molina

Effects of chitosan and plant extracts on growth of Colletotrichum gloeosporioides, anthracnose levels and quality of papaya fruit

The objectives of this research were to evaluate the in vitro fungicidal effect of chitosan and aqueous extracts of custard apple leaves, papaya leaves and papaya seeds, and the combination of chitosan and plant extracts on the development of Colletotrichum gloeosporioides, which causes anthracnose on papaya. Chitosan at 2.0% and 3.0% had a fungicidal effect on C. gloeosporioides. Extracts alone did not show any fungicidal effect while the combination of 2.5% chitosan with all the tested extracts had a fungistatic rather than fungicidal effect. Changes in the conidial morphology of C. gloeosporioides were observed with 1.5% chitosan concentration after 7 h incubation. For in situ studies, control of anthracnose disease was obtained with 1.5% chitosan applied before C. gloeosporioides inoculation. Phomopsis was most frequently isolated from the non-inoculated fruit. Chitosan applications did not influence the content of total solid solubles or percentage weight loss during the storage of papaya fruit. However, there was a tendency toward greater firmness in fruit treated with the papaya seed extract alone or combined with chitosan.

Moisture barrier properties and morphology of mesquite gum–candelilla wax based edible emulsion coatings

Abstract Composite edible coatings were formulated with candelilla wax alone, and candelilla wax blended with beeswax, white mineral oil and oleic acid (2:1 ratios) as the lipid phase, and mesquite gum as the structural material and their corrected water vapor permeability (WVPc) were determined. The coatings were applied to Persian limes and their effect upon physiological weight loss, color and chemical composition changes were evaluated. Addition of the blend of candelilla wax–mineral oil improved the WVPc ( P

New Bioactive Biomaterials Based on Chitosan

Summary Chitosan is a natural polymer, which has become a quite noteworthy material because of its high chemical versatility and functional properties for developing derived compounds with improved or new properties. Among the chemical or enzymatic modifications made to the chitosan molecule are the chitooligosaccharides as well as the grafting of functional groups such as saccharides, oligosaccharides, alkyl groups, cyclodextrins, organic acid, lactide, polylactide, and polyphenol, providing chitosan derivatives with improved solubility and enhanced antimicrobial activity, chelating ability, moisturizing qualities, and healing properties, among others. These new functionalized chitosans have shown high potential for application in medicine, water treatment, pharmaceutical and cosmetic industry, agriculture, and food. This chapter addresses the scope of current functional chitosan derivatives and explains the relationship between chitosan structure and its modifications and the specific properties in the final product as well as its potential applications, particularly in the agricultural and food sectors.

Cactus stem (Opuntia ficus-indica Mill): anatomy, physiology and chemical composition with emphasis on its biofunctional properties

Cactus stem (Opuntia ficus-indica Mill) is native to Mesoamerica and marketed in different forms such as fresh, frozen or pre-cooked. Worldwide, this vegetable is recognized for its pharmaceutical actions, including its antioxidant, diuretic, anticarcinogenic, anti-inflammatory, anti-diabetic, and anti-hypercholesterolemic properties, as well as their antiviral and antispermatogenic effects. However, not all of these properties have been associated with its chemical composition; therefore, this review aims to present and integrate information available on the physiology and anatomy of cactus stem and its chemical composition, focusing on some of the many factors that determine its biofunctionality.