Effects of antimicrobial edible films on the sensory and physical properties of organic spinach in salad bags

Authors: JOSHI, KAMINI - University Of Arizona; SPARKS, PATRICIA - University Of Arizona; Friedman, Mendel; Olsen, Carl; McHugh, Tara; RAVISHANKAR, SADHANA - University Of Arizona

Submitted to: Food and Nutrition Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2021
Publication Date: 2/26/2021
Citation: Joshi, K., Sparks, P., Friedman, M., Olsen, C.W., McHugh, T.H., Ravishankar, S. 2021. Effects of antimicrobial edible films on the sensory and physical properties of organic spinach in salad bags. Food and Nutrition Sciences. 12(2):176-193. https://doi.org/10.4236/fns.2021.122015.
DOI: https://doi.org/10.4236/fns.2021.122015

Interpretive Summary: Essential oils derived from plant sources contain organic compounds that have shown antimicrobial activity. Certified as Generally Recognized as Safe (GRAS) by the FDA, these phyto-antimicrobials are appealing to consumers because they provide a natural alternative to chemical preservatives. Before real world applications can be suggested, the organoleptic effects, as well as changes to the texture and aesthetic appeal of the treated foods, must be evaluated. In the present study, a sensory analysis of organic romaine lettuce was carried out by 75 panelists, of which 35% were identified as Asian/Pacific Islanders, 33% White and 22% Hispanic or Latino as the major ethnicities. Most of the panelists were between 18 and 30 years of age. Romaine lettuce treated with apple films had a higher likelihood of being purchased than those exposed to the other films. The lettuce treated with carrot films had a higher acceptance rating than the lettuce treated with the other films. This study provides an innovative way to apply plant antimicrobials to organic leafy greens without adversely impacting the sensory attributes.

Technical Abstract: The effects of antimicrobial edible films containing carvacrol and cinnamaldehyde on organic baby spinach were determined via sensory analysis and changes in physical properties. Edible films made from pulp of hibiscus, apple,or carrot containing carvacrol or cinnamaldehyde at 0.5%, 1.5%, or 3% concentrations were added to organic baby spinach in plastic bags. These bags were stored at 4°C for 20 - 24 h before performing sensory evaluation and measuring changes in physical properties. A randomized block design with an affective test was used. Preference liking was evaluated based on a 9-point hedonic scale for aroma, color, freshness, mouthfeel, flavor, and overall acceptability. Additionally, panelists quantified each sample using a 5-point hedonic scale for pungency, browning, bitterness, off-odor, and sourness. The color and texture of spinach samples were measured. Edible films containing cinnamaldehyde had the highest preference liking based on aroma, color, freshness, mouthfeel, flavor, and overall acceptability than those containing carvacrol and were the most likely to be purchased by panelists; therefore, cinnamaldehyde can potentially be used as an alternative sanitization option. There were no significant (p = 0.05) changes in firmness or color values between spinach treated with antimicrobial films and controls. The results provide the produce industry with options for incorporating antimicrobial films into salad bags without influencing the physical or sensory properties of baby spinach.