Colletotrichum gloesporioides inhibition using chitosan-Ruta graveolens L essential oil coatings: Studies in vitro and in situ on Carica papaya fruit

Reduction of Postharvest Quality Loss and Microbiological Decay of Tomato “Chonto” (Solanum lycopersicum L.) Using Chitosan-E Essential Oil-Based Edible Coatings under Low-Temperature Storage

“…The preparation of the film-forming emulsions (FFE) based on CS + RGEO followed our previous reported methodology [ 37 ] and as shown in Figure 1 , mixing a specific amount of chitosan (degree of deacetylation = 85%, Mw = 190,000–310,000 Da, Sigma-Aldrich, Palo Alto, CA, USA), with a certain volume of 0.1 M acetic acid a to obtain a 2% w/v solution. Addition of 2.5% v/v of glycerol and Tween 80 (1% v/v ) concerning the final volume of RGEO (Krauter, Bogotá, Colombia) was followed to the complete homogenization using an IKA T25-Digital Ultraturrax (IKA, Staufen, Germany) at 7000 rpm for two minutes.…”

“…The pH was determined with a potentiometer Thermo Fisher Scientific Orion (Waltham, MA, USA) calibrated with 4, 7, and 10 calibration kit Thermo Fisher Scientific Orion (Waltham, MA, USA). Samples used consisted of ten grams of homogenized fruit in 100 mL of distilled water [ 37 ]. Determination of total soluble solids (TSS) (%) used a BRIXCO 0–90% brand refractometer.…”

“…The acidity (citric acid %) was determined using potentiometric titration with 0.1 N NaOH, five grams of fruit homogenized, and 50 mL of distilled water, according to Equation (3) [ 37 ]: where, V 1 is the volume of NaOH used (mL), V 2 is the volume of sample (mL), K is the equivalent weight of citric acid (0.064 g/meq), and N is the normality of NaOH (0.1 meq/mL).…”

“…The color variation in the samples was analyzed accordingly to [ 44 ], identifying the color parameters in the tomatoes according to their maturation stage. The total color difference (Δ E *) was calculated using the following Equation (5) [ 37 ]: …”

“…The proposed study represents an excellent option to complement the antimicrobial activity of chitosan and extend the postharvest stability of tomato “chonto” under refrigeration conditions, improving the stability of tomatoes during 12 days of storage. Based on the vigorous antifungal activity of some RGEO components, the efficiency of CS + RGEO to increase the stability of fruits has been demonstrated by our group in guavas to control Colletotrichum gloesporioides fungi growth and quality aspects [ 16 ], cape gooseberries for microbial and quality assessment, and papayas [ 35 , 36 , 37 ]. This is the first time that the application of CS + RGEO coatings is reported in Tomato var.…”