Sammanfattning

In this study, chlorophyll fluorescence imaging (CFI) was used to monitor plant stress induced by cutting of mini romaine lettuce (Lactuca sativa L. var. longifolia) and by cutting and washing of endive (Cichorium endivia L.) during storage. Regarding the more detailed study of endive fresh-cut salads, we additionally monitored respiratory activity, phenylalanine ammonia lyase (PAL) activity, contents of plant pigments, and cut edge browning. Determination of maximum quantum efficiency F (v)/F (m) was feasible through sealed consumer-sized film bags, thus, enabling the non-invasive monitoring of both fresh-cut salad types in the corresponding modified atmosphere during storage. Cutting of romaine lettuce provoked a partially reversible drop of F (v)/F (m) during the first 24 h. Subsequently, F (v)/F (m) of cut romaine strongly decreased with elapsing shelf life, whereas intact leaves exhibited only a slight decline. Regarding minimally processed endive, warm water washing progressively reduced F (v)/F (m) with increasing heat exposure, while respiratory activities and the content of accessory pigments remained unaffected. The heat-dependent decrease of F (v)/F (m) was correlated to the inhibition of the PAL activity. Mildly warm washing (40 A degrees C, 120 s; 45 A degrees C, 60 s) reduced PAL activities, while F-v/F-m remained widely unaffected and visual quality was only partially improved. However, warm water washing at elevated temperatures (45 A degrees C, 120 s; 50 A degrees C, 30-60 s) enabled maximum visual quality retention, accompanied by a significant decrease of F (v)/F (m). CFI may represent a useful tool to monitor the stress conditions due to cutting and warm water treatments, hence, allowing the systematic improvement of fresh-cut produce.

Nyckelord

Fresh-cut lettuce; Chlorophyll fluorescence imaging; Cutting; Warm water treatments; Modified atmosphere packaging; Phenylalanine ammonia lyase

Publicerad i

Food and Bioprocess Technology
2016, Volym: 9, nummer: 4, sidor: 650-663
Utgivare: SPRINGER

SLU författare

• Menegat, Alexander

  • Institutionen för växtproduktionsekologi, Sveriges lantbruksuniversitet
    
  • Universität Hohenheim

UKÄ forskningsämne

Livsmedelsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1007/s11947-015-1661-2

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/82641