Films and edible coatings based on biopolymers have been developed as a packaging, which can be obtained from biodegradable materials and have properties similar to common plastics. These edible materials have many applications in the food industry, preventing mass transfer between the product and the surrounding environment. The objective of this study was to develop and evaluate the physicochemical and mechanical properties of edible films based on cassava starch (CS), whey protein (WP), and beeswax (BW). Response surface methodology has been used and the experiments were carried out based on face-centred composite design. On the other hand, three CS-based controls were formulated to evaluate the effect of the inclusion of WP and BW. The optimization of multiple responses established the optimal formulation: CS (3.17 %), WP (1.30 %), BW (0.50 %), presenting the following response variables: tensile stress (1.92 MPa), elongation (40.4 %), Young's modulus (42.1 MPa), water vapor permeability 1.79 × 10 −11 (g mm/s cm 2 Pa), swelling capacity (300.3 %), thickness (0.128 mm), moisture content (6.74 %), and colour: lightness (89.9), chromaticity a∗ (-1.8), chromaticity b∗ (7.7), saturation (9.9), tone (101.1°), and yellowness index (17.7). The selection and evaluation of this optimal formulation are essential because it is the material that shows the best possible mechanical and physicochemical properties using the studied components. The results, especially its good mechanical properties and low permeability to water vapour, would allow its application as a coating for fruits, vegetables, among others, effectively delaying its weight loss due to dehydration.

ADDITIONAL INDEX WORDS. mature, index, fat content, dry matter, weather conditions SUMMARY. 'Hass' avocado (Persea americana) is a fruit in high demand in international markets, and Colombia is expanding its export to the United States. Avocado quality and shelf life are related to its harvest time. However, there is not enough information on harvest indicators in Colombia that allow producers to adequately harvest fruit to comply with market requirements. Therefore, the aim of this study was to estimate maturity indicators during two harvest periods. We harvested fruit between the years 2016 and 2017 in eight farms distributed in three regions of the Department of Antioquia, Colombia, and selected those in the postanthesis stages. We assessed variables such as fruit color, weight, dimensions, oil content (OC), and dry matter (DM). The results were analyzed using simple and multiple regressions as well as by principal component analysis (PCA). The results showed a high linear relation between DM and OC (R 2 ‡ 78.88) and a significant relation between OC, rainfall, fruit development time, and environmental temperature. Nondestructive indicators that allow the establishment of DM in the field (R 2 ‡ 73.57) varied according to the region and included fruit color (L*, b*), volume (P £ 0.05), and fruit development time. These indicators could reduce maturity heterogeneity during the harvest period.

The most important issues that affect consumer fruit acceptance in the ‘Hass’ avocado international market are flesh disorders. These defects can be influenced by both pre- and postharvest factors. The aim of this work was to evaluate the effect of the harvest season, storage time, mineral content, and preharvest variables on internal fruit disorders. Here, fruit was sampled from four farms in Antioquia (Colombia) at 22%, 26%, and 30% dry matter (DM) content. Samples were stored and ripened under simulated export conditions. Then, flesh bruising, flesh discoloration, body rots, vascular browning, stem end rot, and mineral content were assessed. The results showed that flesh disorders differ among farms and by harvest index and storage time. The most frequent defects found were vascular browning and stem end rot. Boron, calcium, nitrogen, manganese, magnesium, and potassium have a strong relationship with flesh disorders. Therefore, high boron and calcium contents, as well as a harvest at 26% DM, can substantially reduce avocado flesh disorders and improve internal fruit quality. Farmers that had a high flesh and soil mineral content and low rainfall and temperature produced fruits with fewer internal disorders.

Short steam blanching coupled with flash-vacuum expansion (FVE) and de-pulping was used to obtain purée from purple passion fruits discarded from the export chain. Different steam blanching holding times (80, 95, 110 s) were tested at pressure of 130 kPa. After FVE and vacuum de-pulping, fibers, anthocyanins, carotenoids, rheological properties, and microbial reduction were evaluated in the purées. Fruit purées are obtained with a much higher content of cell-wall and bioactive compounds compared to the fresh arils since part of the fruit shell is incorporated into the purée (approximately 20%), which greatly increases the yield of production. Purées exhibited increasing shear-thinning flow behavior with blanching holding time, resulting in a smoothie-like beverage. A reduction greater than 5 log10 CFU/mL was obtained for molds, yeasts, aerobic mesophilic, and coliforms for all the treatments. The shelf life of smoothies based on nutritional and sensorial quality was extended up to 90 days at refrigeration temperature.

The aim of this research was to evaluate the effect of dry matter as a harvest index and the storage time on the Hass avocado postharvest quality parameters. From four locations, fruit were harvested at three dry matter values: 22, 26 and 30%. After harvest, the external defects, weight, and color fruit were analyzed. The avocados were disinfected and stored (5°C/90%RH during 0, 3, 4 y 5 weeks). After storage, the chilling damage and weight losses were evaluated. After that, fruit were ripened (20°C/90%RH) and the quality aspects of "ready to eat" Hass avocado: color and flesh discoloration were determined. At 26 ± 2% of dry matter, the fruit had the lowest level of defects for the study regions. This means that the avocado fruit quality could improve if the harvest moment and storage time are controlled.