Nitrogen fertiliser rate affects the N-fractions of celery petioles for the fresh processing industry.
Gomez P.A., Madrid R., Artes F.
5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004. page 27
2004
บทคัดย่อ
Nitrogen fertiliser rate affects the N-fractions of celery petioles for the fresh processing industry.
Studies for several vegetable crops have shown that the level of fertiliser applied during the growing season affects the nutrient content of the product.However, knowledge about the effect of the level of nitrate fertiliser on the N-fractions of celery is scarce.The objective of this research was to study the effect of two N fertiliser rates on the protein, nitrate and ammonia contents of celery stalks used as raw material for the minimal fresh processing industry.Celery plants (cv. ‘Istar’) were grown on an inert substrate in a plastic greenhouse where, after the first month, two treatments were applied: a control (NC) with the commonly applied N concentration and a 25% reduction in N concentration (NR).Remaining nutrients were kept at the same level for NR and NC.Plants were hand harvested and the following fractions were prepared: leaves, petioles, bud, basal disc and roots.Total N, N-protein, N-nitrate and N-ammonia contents were analysed.The protein content of the petioles (fraction used by the industry for producing celery sticks) was not affected by the level of fertiliser.However, a positive correlation was found between the rate of N fertiliser and the nitrate and ammonia concentration.Since the ingestion of excessive amounts of nitrate can cause adverse effects on health, celery grown under 25% lower N supply could be considered an safer from the nutritional point of view and, at the same time, with and adequate level of proteins.Organoleptic properties were not affected by the rate of fertiliser.