Production of Volatiles in Fresh‐Cut Apple: Effect of Applying Alginate Coatings Containing Linoleic Acid or Isoleucine

Abstract

One of the main quality parameters in apples is aroma, its main precursors are fatty acids (FA) and amino acids (AA). In this study, alginate edible coatings were used as carriers of linoleic acid or isoleucine to serve as precursors for the production of aroma in cut apples. Apple wedges were immersed in a CaCl2 solution and coated with one of the following formulations: alginate solution (Alg-Ca), Alg-Ca-low-level linoleic acid (0.61 g/Lt), (LFA), Alg-Ca-high-level linoleic acid (2.44 g/L; HFA), Alg-Ca-low-level isoleucine (0.61 g/L; LAA), and Alg-Ca-high-level isoleucine (2.44 g/L; HAA). Apple wedges were stored at 3 °C and 85% relative humidity for 21 d and key volatiles were studied during storage. Addition of precursors, mainly isoleucine, showed to increase the production of some key volatiles on coated fresh-cut apples during storage. The concentration of 2-methyl-1-butanol was 4 times higher from day 12 to day 21 in HAA, while 2-methyl butyl acetate increased from day 12 to day 21 in HAA. After 21 d, HAA-apples presented a 40-fold value of 2-methyl-butyl acetate, compared to Alg-Ca cut apples. Values of hexanal increased during cut apple storage when the coating carried linoleic acid, mainly on HFA, from 3 to 12 d. The ability of apples to metabolize AA and FA depends on the concentration of precursors, but also depends on key enzymes, previous apple storage, among others. Further studies should be done to better clarify the behavior of fresh-cut apples as living tissue to metabolize precursors contained in edible coatings for the production of volatiles.

Production of edible coatings with twin‐nozzle electrospraying equipment and the effects on shelf‐life stability of fresh‐cut apple slices

“…), the secondary packaging material use or modified atmosphere applications, as well as the storage conditions (period, temperature, relative humidity). The linear incline of the water loss was observed in the present study similar to the literature (Maya‐Meraz et al, ; Olivas, Mattinson, & Barbosa‐Cánovas, ; Qi, Hu, Jiang, Tian, & Li, ; Song, Jo, Song, Min, & Song, ). The water content of the emulsion had an impact on the droplet size depending on the emulsion conductivity and thus the electrospraying properties; however, there was no significant impact of the droplet size on the water loss percent of electrospray coated apple samples.…”

“…It was stated that, lipid incorporated edible coatings have low water vapor permeability values with respect to their hydrophobic nature, and even some of the lipids have such lower water vapor permeability that is (Morillon et al, 2002). And thus the moisture loss of the fresh-cuts can be reduced by applying lipid based coatings on fresh-cut fruits (Chiumarelli & Hubinger, 2012;Maya-Meraz et al, 2014). There is a vast amount of studies about fresh-cut apple coating applications and the water loss % of the coated apple slices were found changing between 5 and 20%, depending on the apple cultivar, the coating material formulation (protein, polysaccharide or lipid based), the structure of coating material ( found similar up to 20% water content; however, over this rate (25-30%), the emulsions were stated as less reproducible.…”

VOLATILE COMPOUNDS IN GOLDEN DELICIOUS APPLE FRUIT (Malus domestica) DURING COLD STORAGE

“…Volatiles concentration in apples was determined by gas chromatography-mass spectrometry (GC-MS) using the solid phase microextraction (SPME) technique, as described by Maya-Meraz et al (2014). Apple juice from eight apples per treatment was obtained with a food processor (Turmix, México).…”

Aroma profile of Fuji apples treated with gelatin edible coating during their storage

“…Gelatin-starch coatings prolonged the postharvest shelf life of avocado (Aguilar-Méndez, San Martín-Martínez, Tomás, Cruz-Orea, & Jaime-Fonseca, 2008) and 10% gelatin coating, besides delaying ripening of mango fruit by suppressing the activity of softening enzymes, allowed the retention of higher ascorbic acid and phenolic content as compared with control (Gol & Ramana Rao, 2013). In the last few years, many scientific publications focused on physical and organoleptic changes in fruits covered with ECs, but at the best of our knowledge, only very few papers deal with aroma profile of coated apple fruit (Maya-Meraz et al, 2014;Sepulveda & Olivas, 2016;Olivas, Mattinson, & Barbosa-Cánovas, 2007)), and no paper assessed possible changes in volatile organic compounds (VOCs) induced by gelatin coating.…”