Cold Temperature Delays Wound Healing in Postharvest Sugarbeet Roots

Abstract

Storage temperature affects the rate and extent of wound-healing in a number of root and tuber crops. The effect of storage temperature on wound-healing in sugarbeet (Beta vulgaris L.) roots, however, is largely unknown. Wound-healing of sugarbeet roots was investigated using surface-abraded roots stored at 6 and 12°C for 28 days. Surface abrasions are common injuries of stored roots, and the storage temperatures used are typical of freshly harvested or rapidly cooled roots. Transpiration rate from the wounded surface and root weight loss were used to quantify wound healing. At 12°C, transpiration rate from the wounded surface declined within 14 days and wounded roots lost weight at a rate similar to unwounded controls. At 6°C, transpiration rate from the wounded surface did not decline in the 28 days after injury, and wounded roots lost 44% more weight than controls after 28 days storage. Melanin formation, lignification, and suberization occurred more rapidly at 12°C than at 6°C, and a continuous layer of lignified and suberized cells developed at 12°C, but not at 6°C. Examination of enzyme activities involved in melanin, lignin, and suberin formation indicated that differences in melanin formation at 6 and 12°C were related to differences in polyphenol oxidase activity, although no relationships between suberin or lignin formation and phenylalanine ammonia lyase or peroxidase activity were evident. Wound-induced respiration was initially greater at 12°C than at 6°C. However, with continued storage, respiration rate of wounded roots declined more rapidly at 12°C, and over 28 days, the increase in respiration due to injury was 52% greater in roots stored at 6°C than in roots stored at 12°C. The data indicate that storage at 6°C severely slowed and impaired wound-healing of surface-abraded sugarbeet roots relative to roots stored at 12°C and suggest that postharvest losses may be accelerated if freshly harvested roots are cooled too quickly.

High oxygen facilitates wound induction of suberin polyphenolics in kiwifruit

“…oxygen atmosphere, temperature, and humidity). Under favorable conditions, the process of suberization and melanin formation proceeds rapidly . Oxygen was an essential substrate for melanin formation, and was required for PAL, POD, and CAT in catalyzing the formation of SPP.…”

The Harvest Season Changes the Organoleptic Properties of Onion during Storage

“…The reduction of phenolic compounds with subsequent increase is possibly related to the biosynthesis of flavonoids, mainly quercetin. The non-structural sugars increase in onion bulbs during storage [42,43,44] to provide metabolic energy for flavonoid biosynthesis [45]. The increase in flavonoid content, especially quercetin, at the end of storage is related to formation and brown staining of onion peel [46], breakage of dormancy and budding [45].…”

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“…Half of the corms were wounded superficially (2-3 times) by scraping with a steel brush (Sodomar 25 cm) one hour after harvest and the remaining corms were used as unwounded controls. Wounded and unwounded corms were stored 12 ± 4 °C and 90 ± 5% relative humidity for 21 d (Fugate et al, 2016). The corms were evaluated after 0, 1, 2, 3, 4, 5, 6, 7, 14 and 21 d of storage.…”

“…Tissue Darkening-Tissue darkening was assessed by visual analysis (Fugate et al, 2016). The images were captured with a Sony Cyber-Shot DSC-HX1 semiprofessional camera.…”

“…The images were captured on a Zeiss Axioskop microscope (Jena, Germany) equipped with a Zeiss AxioCam color camera. Tissue sections were stained with 5 N HCL-saturated phloroglucinol and examined under standard light microscopy for lignification detection (Sabba & Lulai, 2002;Fugate et al, 2016). Lignification sites were identified by the specific reaction of the reagent with the coniferylaldehyde groups (Sarkanen & Ludwig, 1971) and cinnamaldehyde (Geiger & Fuggerer, 1979) resulting in an orange-reddish coloration.…”