EFFECT OF HARVEST DATE ON THE SHELF-LIFE OF ASPARAGUS

Commercial asparagus production occurs over an extended period in spring from carbohydrate reserves built up during the previous summer and stored in the roots. The effect of harvest duration on spear yield and quality, and on the depletion of storage root carbohydrates has been widely studied. However, little work has been reported on the effect of harvest period on the storage life and biochemistry of asparagus spears. Therefore, asparagus spears (Asparagus officinalis L. cv. Limbras 10) were harvested over the commercial harvesting season in 2 years and held at 20-degrees-C to assess shelf life and to monitor postharvest biochemistry. Shelf life declined almost linearly in both years from c. 6 days for early-season spears to c. 3 days for late-season spears. On the evidence of rates of protein and carbohydrate loss, and ammonia accumulation in the spear tips, the decline in shelf life was not associated with accelerated biochemical changes. Spear fresh weight at harvest (and therefore spear thickness) was strongly associated with shelf life. The shelf life of spears can be predicted from their harvest date.