Abstract
The Myrtillocactus geometrizans (Mart. ex. Pfeiff.) fruit, locally called garambullo, is an important source of bioactive compounds, mainly betalains, polyphenols, and ascorbic acid. However, information on the application of post-harvest technologies that prolong the shelf life of the fruits is still insufficient. The objective of the present research was to evaluate the effect of a gelatin coating incorporating 0%, 1%, or 3% tomato oily extract (TOE), compared to a control (without coating), on the physicochemical and antioxidant properties of garambullo fruits stored for 15 days at 5 °C. The gelatin coatings with TOE significantly (p ≤ 0.05) delayed changes in weight loss, brix degrees, titratable acidity and pH, compared to the control during storage. Fruits coated with TOE-gelatin had a higher content of betalains, ascorbic acid, total phenols, and flavonoids. The results showed that a higher concentration of phytochemicals increased antioxidant activity in vitro; the maximum values found for Trolox equivalents per kg of fresh weight were 10.46 and 17.65 mM for the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and Trolox Equivalent Antioxidant Capacity Method (TEAC) tests, respectively. The gelatin coating with TOE-3% (COTE-3%) reduced water loss by 1.66 times, compared to the control. In addition, the fruits covered with COTE-3% showed the highest concentration of bioactive compounds during storage.
Highlights
Weight loss in fruits is associated with water loss by metabolic processes such as transpiration and respiration, and the rate of water loss depends on the pressure gradient of the water in the fruit tissue and the surrounding atmosphere, and the storage temperature [11,26]
Based on the results shown in this research, it is inferred that gelatin coatings with tomato oily extract (TOE) retard the metabolic processes of the fruit and, extend its shelf life in cold storage
The results of this research show that gelatin coatings incorporated with tomato oily extracts are highly efficient in protecting garambullo fruits that are in storage at 5 ◦ C
Summary
Pfeiff.) is an endemic cactus that presents Crassulacean acid metabolism photosynthesis; it grows in the arid and semi-arid areas of Mexico. This species produces an edible fruit, commonly called ‘garambullo’. The fruit is globular in shape, with a diameter of 1.5 cm. The fruit pulp has a soft and juicy consistence, and is red to a darker purple [1]. Its sensory properties make it a favorite with the locals [2]. Information about the fruit’s physicochemical properties, bioactive compounds, and antioxidant activity is limited. There are no established parameters that allow the identification of the optimum ripening of the fruit for harvesting; Agronomy 2018, 8, 248; doi:10.3390/agronomy8110248 www.mdpi.com/journal/agronomy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
