Impact of Plant-Based Antimicrobial Washes on Sensory Properties of Organic Leafy Greens

Abstract

The objective was to study the sensory attributes of organic leafy greens treated with plant antimicrobials and identify treatments most accepted by panelists. Organic leafy greens were washed with antimicrobials and stored at 4°C for 24 h prior to serving panelists. Antimicrobials evaluated include: 0.1% clove bud, lemongrass, oregano, or cinnamon essential oils; 0.1% carvacrol or citral; 3% grapeseed, apple, or 10%/7% olive extract; combination of essential oils with extracts; 3% hydrogen peroxide; and untreated control. A randomized block design with an affective test was used and 60 panelists were asked to evaluate samples for preference liking based on a 9-point hedonic scale and for sensory attributes based on a 5-point hedonic scale. Changes in texture and color of leafy greens were measured using a Texture analyzer and a Chroma Meter, respectively. On the basis of preference liking, overall acceptability of spinach and lettuce treated with 0.1% cinnamon oil was ranked the highest (7.5 ± 1.4 and 7.1 ± 1.7, moderately liked), respectively. For texture analysis, washing iceberg lettuce with 0.1% oregano oil + 10% olive extract and spinach with 0.1% lemongrass oil + 1% apple extract yielded the highest firmness values of F = 783.1 ± 53.8 Newtons and 939.30 ± 35.2 Newtons, respectively. Based on the International Commission on Illumination CIE LAB color schemes, treatment with 0.1% oregano oil + 10% olive extract had the greatest impact on color of iceberg lettuce with the lowest L value* (44.5 ± 6.2) indicating the darkest color. These results will help identify plant antimicrobials that have the least impact on sensory properties of organic leafy greens and are preferred by consumers.