Hazelnuts are an economically important nut which is consumed world-wide.It is prone to infection by Aspergillus flavus and contamination with aflatoxins.Taking Tukey’s hazelnuts as a research object,the objective of...Hazelnuts are an economically important nut which is consumed world-wide.It is prone to infection by Aspergillus flavus and contamination with aflatoxins.Taking Tukey’s hazelnuts as a research object,the objective of this study were to(a)quantify respiration rates and(b)dry matter losses(DMLs)and(c)aflatoxin B_(1)(AFB_(1))contamination of naturally stored shelled hazelnuts at different temperatures and water availabilities.Subsequently,shelled hazelnuts were inoculated with additional A.flavus inoculum prior to storage to examine effects on dry matter losses and on AFB_(1) contamination.Maximum respiration of hazelnuts and associated mycoflora was under wetter conditions of 0.90~0.95 water activity(aw=12.5%~18%moisture content).This resulted in between approx.10%DML at 25 and 30℃after 5 days storage.Inoculation and storage of shelled hazelnuts+A.flavus inoculum resulted in similar patterns of respiration with optimal levels at 25~30℃and>0.90 aw.Indeed,AFB_(1) contamination was highest at the maximum water levels tested of 0.90 aw.Indeed the contamination level exceeded the legislative limits set by the EU for AFB_(1) contamination of these nuts.Correlation between DMLs and all the AFB_(1) data in both sets of studies showed that very small changes in DML due to poor drying or storage of≥0.6%resulted in AFB_(1) contamination levels exceeding the EU legislative limits.Thus,efficient drying and safe monitored storage is necessary to minimise the risk of AFB_(1) contamination in this economically important commodity and to avoid exposure of consumers to such toxins.展开更多
Essential plant nutrients contained in residues and wastes generated during biofuel processing can be recovered for further production of bioenergy biomass. The objective of this study was to determine the relative ag...Essential plant nutrients contained in residues and wastes generated during biofuel processing can be recovered for further production of bioenergy biomass. The objective of this study was to determine the relative agronomic efficiency of “processed” biofuel residual (PBR). Liquid biofuel residual was “processed” by precipitating phosphate and ammonium in the residual with magnesium into a struvite-like material. Then, in a series of greenhouse experiments, we evaluated the fertility potential of PBR, using sweet sorghum (Sorghum bicolor (L.) Moench), as a test bioenergy crop. We compared the agronomic effectiveness of PBR to inorganic commercial fertilizers, biosolids, and poultry manure as nutrient sources. The sources were either applied alone or in combination with supplemental essential plant nutrients (S, K, Mg, and micronutrients). In each of the greenhouse experiments, the crop was grown for 12 wk on soil of minimal native fertility. After each harvest, sufficient water was applied to the soil in each pot over a 6-wk period to yield ~2 L (~one pore volume) of leachate to assess potential total N and soluble reactive phosphorus (SRP) losses. Dry matter yields from the PBR treatment applied alone were significantly greater than yields from inorganic fertilizers, biosolids, and poultry manure treatments applied alone, and similar to yields obtained when the supplemental essential plant nutrients were added to the inorganic fertilizer, biosolids, and manure treatments. Leachate N and SRP concentrations from the PBR treatment were significantly lower than in the treatments with inorganic fertilizers, poultry manure, and biosolids. We conclude that PBR can substitute for inorganic fertilizers and other organic sources of plant nutrients to produce bioenergy biomass cheaply, without causing offsite N and P losses in vulnerable soils.展开更多
Potatoes have to be stored after harvest for a shorter or longer period in order to maintain even supply to the market throughout the year for direct human consumption as well as for the processing industry. The prese...Potatoes have to be stored after harvest for a shorter or longer period in order to maintain even supply to the market throughout the year for direct human consumption as well as for the processing industry. The present study focused on the storage potentialities of six exotic varieties of potato viz., Diamant, Cardinal, Granola, Felsina, Provento and Asterix at farmers’ condition. The experiment was conducted during winter (December to March) for cultivation, and spring and summer (March to August) for storage at Domar Foundation Seed Potato Production Farm, BADC, Nilphamari, Bangladesh. Results revealed that there were significant variations in storage behavior among the varieties of potato tubers. Asterix showed minimum weight loss (7.10%) which was statistically identical with Cardinal (7.85%) while it was maximum in Felsina (18.83%) followed by Provento (13.41%) during four months storage conditions practicing by farmers (farmers’ conditions). In respect of rotting, significantly highest degree was found in Felsina (18.72%) followed by Provento (15.01%) and the lowest was in Asterix (2.02%) identically similar with Granola (2.22%). The highest percentage of water loss was found in Provento (27.01%) and the lowest was recorded in Asterix (17.03%). Dormancy period and sprouts per tuber were found highest in Asterix (70 days and 9.67) while the lowest dormancy was in Diamant (56 days) and the lowest sprouting was in Granola (2.50). Asterix was found to produce significantly highest amount of dry matter content (20.50%) along with higher amount of edible stored tubers (80.21%) compared to those of other varieties at the end of four months storage. Under the same condition, Diamant was the second highest producer of dry matter (20%) which was statistically similar with Asterix, and had good storage ability that retained 69.07% edible tubers, whereas Felsina contained the lowest amount of dry matter (16%) and showed poor storage ability retaining 55.85% edible tubers. Based on the results, Asterix possessed better keeping quality with long dormancy, minimum weight loss, higher tuber dry matter with edible tuber, excellent storage ability, low storage losses and rotting. However, the variety Asterix may be recommended for commercial storage under ordinary storage condition or farmers’ practice. Diamant ranked in second position considering the above circumstances, although showed better performances compared to the rest of the studied varieties.展开更多
文摘Hazelnuts are an economically important nut which is consumed world-wide.It is prone to infection by Aspergillus flavus and contamination with aflatoxins.Taking Tukey’s hazelnuts as a research object,the objective of this study were to(a)quantify respiration rates and(b)dry matter losses(DMLs)and(c)aflatoxin B_(1)(AFB_(1))contamination of naturally stored shelled hazelnuts at different temperatures and water availabilities.Subsequently,shelled hazelnuts were inoculated with additional A.flavus inoculum prior to storage to examine effects on dry matter losses and on AFB_(1) contamination.Maximum respiration of hazelnuts and associated mycoflora was under wetter conditions of 0.90~0.95 water activity(aw=12.5%~18%moisture content).This resulted in between approx.10%DML at 25 and 30℃after 5 days storage.Inoculation and storage of shelled hazelnuts+A.flavus inoculum resulted in similar patterns of respiration with optimal levels at 25~30℃and>0.90 aw.Indeed,AFB_(1) contamination was highest at the maximum water levels tested of 0.90 aw.Indeed the contamination level exceeded the legislative limits set by the EU for AFB_(1) contamination of these nuts.Correlation between DMLs and all the AFB_(1) data in both sets of studies showed that very small changes in DML due to poor drying or storage of≥0.6%resulted in AFB_(1) contamination levels exceeding the EU legislative limits.Thus,efficient drying and safe monitored storage is necessary to minimise the risk of AFB_(1) contamination in this economically important commodity and to avoid exposure of consumers to such toxins.
文摘Essential plant nutrients contained in residues and wastes generated during biofuel processing can be recovered for further production of bioenergy biomass. The objective of this study was to determine the relative agronomic efficiency of “processed” biofuel residual (PBR). Liquid biofuel residual was “processed” by precipitating phosphate and ammonium in the residual with magnesium into a struvite-like material. Then, in a series of greenhouse experiments, we evaluated the fertility potential of PBR, using sweet sorghum (Sorghum bicolor (L.) Moench), as a test bioenergy crop. We compared the agronomic effectiveness of PBR to inorganic commercial fertilizers, biosolids, and poultry manure as nutrient sources. The sources were either applied alone or in combination with supplemental essential plant nutrients (S, K, Mg, and micronutrients). In each of the greenhouse experiments, the crop was grown for 12 wk on soil of minimal native fertility. After each harvest, sufficient water was applied to the soil in each pot over a 6-wk period to yield ~2 L (~one pore volume) of leachate to assess potential total N and soluble reactive phosphorus (SRP) losses. Dry matter yields from the PBR treatment applied alone were significantly greater than yields from inorganic fertilizers, biosolids, and poultry manure treatments applied alone, and similar to yields obtained when the supplemental essential plant nutrients were added to the inorganic fertilizer, biosolids, and manure treatments. Leachate N and SRP concentrations from the PBR treatment were significantly lower than in the treatments with inorganic fertilizers, poultry manure, and biosolids. We conclude that PBR can substitute for inorganic fertilizers and other organic sources of plant nutrients to produce bioenergy biomass cheaply, without causing offsite N and P losses in vulnerable soils.
文摘Potatoes have to be stored after harvest for a shorter or longer period in order to maintain even supply to the market throughout the year for direct human consumption as well as for the processing industry. The present study focused on the storage potentialities of six exotic varieties of potato viz., Diamant, Cardinal, Granola, Felsina, Provento and Asterix at farmers’ condition. The experiment was conducted during winter (December to March) for cultivation, and spring and summer (March to August) for storage at Domar Foundation Seed Potato Production Farm, BADC, Nilphamari, Bangladesh. Results revealed that there were significant variations in storage behavior among the varieties of potato tubers. Asterix showed minimum weight loss (7.10%) which was statistically identical with Cardinal (7.85%) while it was maximum in Felsina (18.83%) followed by Provento (13.41%) during four months storage conditions practicing by farmers (farmers’ conditions). In respect of rotting, significantly highest degree was found in Felsina (18.72%) followed by Provento (15.01%) and the lowest was in Asterix (2.02%) identically similar with Granola (2.22%). The highest percentage of water loss was found in Provento (27.01%) and the lowest was recorded in Asterix (17.03%). Dormancy period and sprouts per tuber were found highest in Asterix (70 days and 9.67) while the lowest dormancy was in Diamant (56 days) and the lowest sprouting was in Granola (2.50). Asterix was found to produce significantly highest amount of dry matter content (20.50%) along with higher amount of edible stored tubers (80.21%) compared to those of other varieties at the end of four months storage. Under the same condition, Diamant was the second highest producer of dry matter (20%) which was statistically similar with Asterix, and had good storage ability that retained 69.07% edible tubers, whereas Felsina contained the lowest amount of dry matter (16%) and showed poor storage ability retaining 55.85% edible tubers. Based on the results, Asterix possessed better keeping quality with long dormancy, minimum weight loss, higher tuber dry matter with edible tuber, excellent storage ability, low storage losses and rotting. However, the variety Asterix may be recommended for commercial storage under ordinary storage condition or farmers’ practice. Diamant ranked in second position considering the above circumstances, although showed better performances compared to the rest of the studied varieties.
