NUTRIENT AND MINERAL COMPOSITION OF CITRUS PULP

Transcription

1 AMMERMAN, MARTIN, ARRINGTON: CITRUS PULP 0 quality and a diet containing as much as 0% of this feedstuff was readily consumed by sheep. feed intakes and average daily gains were not significantly influenced by the dietary treatment. Water consumption, however, was significantly increased by feeding the magnesium pulp and resulted in soft, watery feces and ex tremely wet bedding. Blood plasma calcium and phosphorus levels were not influenced by treat ment but plasma magnesium tended to increase as the dietary intake of magnesium increased. Acknowledgments The authors wish to acknowledge Basic Chem icals, Cleveland, Ohio, and the Florida Citrus Processors Association, in cooperation with the Florida Citrus Commission for funds in support of this study; and Dawes Laboratory, Inc., Chi cago,., for supplying vitamins A and D. The technical assistance of Chandra Aulsbrook, Bar bara King and A. F. Castro is acknowledged. LITERATURE CITED Nutrient Composition of Dried Citrus Pulp. Proc. Fla. State Hort. Soc. :.. Ammerman, C. B., F.G. Martin and L. R. Arrington.. Nutrient and Mineral Composition of Citrus Pulp as Related to Production. Proc. Fla. State Hort. Soc. :?. Bartlett, G. R.. Phosphorus Assay in Column Chromatography. J. Biol. Chem. :.. Chicco, C. F.. Some Nutritional Aspects of Die tary Magnesium in Ruminants and Poultry. Ph.D. Disserta tion. University of Florida.. Dowe, T. W., J. Matsushima and V. H. Arthaud.. The Effects of Adequate and Excessive Calcium When Fed with Adequate Phosphorus in Growing Rations for Beef Calves. J. Animal Sci. :.. Duncan, D. B.. Multiple Range and Multiple F Tests. Biometrics :.. Hendrickson, R. and J. W. Kesterson.. ByProd ucts of Florida Citrus Composition, Technology, and Utilization. Fla. Agr. Exp. Sta. Bui... Kendall, K. A., K. E. Harshbarger, R. L. Hays and E. E. Ormiston.. Incidence of Parturient Paresis and Blood Composition of Paretic Suspects Associated with Prepartum s of Concentrate Feeding. J. Dairy Sci. :.. Kendall, K. A., K. E. Harshbarger, R. L. Hays and E. E. Ormiston.. Serum s of Certain Constitu ents in Paretic and Pareticsuspect Cows. J. Dairy Sci. :. 0. Parker, H. E.. Magnesium, Calcium, and Zinc in Animal Nutrition. PerkinElmer Atomic Absorption Newsletter, No... Stott, G. H.. Parturient Paresis Related to Dietary Phosphorus. J. Dairy Sci. :.. Wise, M. B., A. L. Ordoveza and E. R. Barricfc.. Influence of Variations in Dietary Calcium: Phos phorus Ratio on Performance and Blood Constituents of Calves. J. Nutr. :.. Ammerman, C. B., J. F. Easley, L. R. Arrington and F. G. Martin.. Factors Affecting the Physical and NUTRIENT AND MINERAL COMPOSITION OF CITRUS PULP AS RELATED TO PRODUCTION SOURCE C. B. Ammerman, F. G. Martin, and L. R. Arrington Department of Animal Science, Florida Agricultural Experiment Station, Gainesville Dried citrus pulp has been used as a feed for a number of years and average values repre senting content of the major nutrients is gen erally well known. Nutrient content in terms of ash, protein, ether extract, crude fiber and ni trogenfree extract of citrus pulp samples col lected over a threeyear period has been reported (). Information concerning the mineral com position of pulp is limited. The present study was made to determine the proximate nutrients and certain macro and micro minerals in citrus pulp and to relate composition to production source. Florida Agricultural Experiment Stations Journal Series No.. Experimental Procedure Proximate analyses of 0 samples of citrus pulp collected during and were made and combined with similar data published pre viously () from samples of pulp obtained during,, and and all data were summarized. The samples had been collected and analyzed by the Feed Laboratory, Division of Chemistry, Florida Department of Agricul ture. To make comparisons in nutrient composi tion of pulp between production sources, the analyses for samples representing pro duction locations over the fiveyear period were suitable for use. During and the first quarter of, a portion of every fourth citrus pulp sample collected by the Feed Laboratory was made available to the Nutrition Laboratory for min eral analyses. Calcium, magnesium, phosphorus, potassium and sodium were determined on samples and iron, copper, zinc and manganese

2 0 FLORIDA STATE HORTICULTURAL SOCIETY, were determined an samples. Sulfur and cobalt were determined on 0 samples selected randomly from the same period. To avoid con tamination, all trace elements were determined on unground samples. Chemical analyses for moisture, ash, protein, ether extract, and crude fiber were conducted according to AOAC (). An atomic absorption spectrophotometer was used to determine cal cium, magnesium, sodium, potassium, copper, zinc, iron and manganese. The method of Marston and Dewey () was used for the determina tion of cobalt. Calcium and magnesium were determined by the method of Parker () and the other elements were determined as outlined by the manufacturer (). Analysis of sulfur was made by oxidation with an oxygen bomb and proceeding according to the method of AOAC (). The method of Bartlett () was used for phosphorus analysis. The data were subjected to analysis of variance with significant differences between means determined by the multiple range test of Duncan (). The multiple range test is considered as approximate since no adjustments were made for unequal sample sizes. The average number of samples per observation was determined and Duncan's test was performed as if every mean were based on this number of observations. Results and Discussion The average nutrient composition of the cit rus pulp samples collected over a fiveyear period is shown in table. A total of samples are represented in the yearly averages but only in the combined averages. The combined average values vary only slightly from those reported previously for the first three years of data (). The moisture content of pulp sam ples as collected varied from. to.% with an average of.%. It is recognized that the total nutritive value of a particular sample of pulp is influenced by its moisture content. To make more meaningful comparisons among years and among production sources, therefore, all data are expressed on a dry matter basis. Ex pressed on this basis, the average nutrient com position for the samples was as follows: ash,.; ether extract,.0; protein,.; crude fiber,.; and nitrogenfree extract, 0.0%. Except for differences in ether extract TABLE. AVERAGE NUTRIENT COMPOSITION OF CITRUS PULP SAMPLES COLLECTED OVER A FIVEYEAR PERIOD Nutrients, % Year Number of Samples Moisture Ash Ether Extract Protein/ Crude Fiber Nitrogenfree Extract Airdry Basis / ' Range Dry matter Basis Combined ^ ; 0 Kjeldahl nitrogen x.. / Total number of samples does not equal sum of samples for individual years. For year to year comparisons and.combined averages, data.were excluded if less than two samples were available for each production source each year.

3 AMMERMAN, MARTIN, ARRINGTON: CITRUS PULP 0 and protein content, the average nutrient com position of pulp varied only slightly from year to year. The average nutrient composition of the cit rus pulp samples according to production source is shown in table. Significant (P<.0) dif ferences were found among production sources for all nutrients. The comparison as shown is based on the fiveyear average. Within year com parisons revealed that the relative differences among the production sources were not the same for each of the five years. In general, however, a production source having pulp samples "high" in crude fiber, for example, for one year would have similar samples for other years although there was variation in the relative rank of the particular production source during the fiveyear period. The average ether extract content by producton source varied from. to.%, and the standard deviation within production source was ±.%. The protein content ex pressed on a similar basis, varied from. to.0% and tended to be correlated with the ether extract content of the sample. The varia tion in ether extract and protein content may have been related to the amount of seeds present in the pulp. Ammerman et ah () reported that for each % increment of citrus seeds substi tuted for peel plus pulp, ether extract was in creased by about 0.% and protein by 0.0%. The peel plus pulp fraction, devoid of seeds, has been reported to contain.% ether extract and.0% protein on a dry matter basis (). As shown in table, there was an inverse rela tionship between level of crude fiber and level of nitrogenfree extract. Citrus pulp samples from several production sources known to be producing molasses tended to be high in crude fiber and low in nitrogenfree extract. The average mineral composition of citrus pulp samples is shown in table. Calcium con tent of the pulp varied from 0. to.% with an average of.% when expressed on a dry matter basis. The amount of lime (calcium oxide or calcium hydroxide) required as a dewatering agent in the dehydration of fresh pulp TABLE. AVERAGE NUTRIENT COMPOSITION OF CITRUS PULP SAMPLES COLLECTED OVER A FIVEYEAR PERIOD EXPRESSED IN PERCENT ACCORDING TO PRODUCTION SOURCE^ Nitrogenfree Moisture Ash Ether Extract Protein' Crude Fiber Extract U [ O Std. Dev.' Twentytwo to samples represented by each production source for a total of samples. All values except moisture are expressed on a dry matter basis. All values in the same column not covered by the same line are significantly (P <.0) different. Kjeldahl nitrogen x.. Within production source standard /deviation.

4 0 FLORIDA STATE HORTICULTURAL SOCIETY, varies with the type and condition of the wet pulp (). Thus, some variability in the calcium content of the dried pulp is expected. It appears, however, that less calcium is being added to citrus pulp at the present time than was added previously. Kirk and Davis () reported in that calcium in dried citrus pulp expressed on an airdry basis ranged from. to.% and higher. This is equavalent to. to.% calcium on a dry matter basis. The use of the minimum level of calcium required for the pro duction of high quality pulp is desirable. Such pulp can be used at higher dietary levels with out unduly increasing the total dietary calcium intake. It should be emphasized that the levels of calcium listed on the feed tags for citrus pulp are shown as maximum levels for legal purposes and serve almost no value from a nutritional standpoint. The level of calcium appearing on the tag may be near to, or some two to three times the actual level of calcium in the pulp. The average magnesium and phosphorus levels of the pulp samples were 0. and 0.%, respectively. Similar levels have been reported previously (, ). A few samples con tained "high" levels of phosphorus perhaps because of a disproportionately greater number of seeds present in the sample. The average composition for the other macro minerals was as follows: potassium,.0%; sodium, 0.0%; and sulfur, 0.0%. The average composition for the micro minerals expressed in ppm was as follows: iron,.; copper,.; zinc,.; manganese,.0; and cobalt, 0.0. The average mineral composition of the cit rus pulp samples according to production source is shown in tables and. Significant (P<.0) differences were found among production sources for all minerals except manganese, copper and zinc. The average calcium content of the pulp by production source varied from.0 to.0% and the standard deviation within source was ±0.%. The changes in magnesium, phos phorus and potassium levels among production sources tended to be gradual and of uniform magnitude. The levels of sodium followed a similar trend except that for an unexplained reason, the highest average level of sodium was almost twice that of the next highest level of sodium. A similar pattern was observed with copper in that the highest level according to production source was.0 ppm followed by a level of.0 ppm for the next source. There was little variability in manganese levels of pulp from various sources (.0 to.0 ppm) and zinc varied from. to. ppm due to source. The levels of iron in pulp were quite variable among sources and ranged from.0 to. ppm. It may be that the total iron level as well as the variability in iron content were influenced by contamination with iron from machinery dur ing the production process. TABLE. AVERAGE MINERAL COMPOSITION OF CITRUS PULP SAMPLES COLLECTED DURING AND FIRST QUARTER / Macro minerals, % Calcium Magnesium Phosphorus Potassium Sodium Sulfur Range Std. Dev.'' Micro minerals, ppm Iron Copper Zinc Manganese Cobalt Range Std. Dev.^ / All values expressed on a dry matter basis. Eightytwo samples for all macro minerals except sulfur. Ten samples for sulfur. Standard deviation. / Thirtyfive samples for all micro minerals except cobalt. Ten samples for cobalt.

5 AMMERMAN, MARTIN, ARRINGTON: CITRUS PULP 0 TABLE. AVERAGE MACRO MINERAL COMPOSITION OF CITRUS PULP SAMPLES COLLECTED DURING.. > AND FIRST QUARTER EXPRESSED IN PERCENT ACCORDING TO PRODUCTION SOURCE^' Calcium Magnesium Phosphorus Potassium Sodium Sourc e ; , Std. / Dev Three to samples represented by each production source for a total of samples. All values expressed on a dry matter basis. All values in the same column not covered by the same line are significantly (P <.0) different. / Within production source standard deviation. Summary The nutrient analyses of samples of dried citrus pulp obtained by the Feed Labora tory, Division of Chemistry, Florida Department of Agriculture during the years were summarized. The average moisture content for all samples was.% and expressed on a dry matter basis, the average proximate composi tion was as follows: ash,.%; protein,.%; TABLE. AVERAGE.MICRO MINERAL COMPOSITION OF CITRUS PULP SAMPLES COLLECTED DURING AND FIRST QUARTER EXPRESSED IN PARTS PER MILLION ACCORDING TO PRODUCTION SOURCE Iron Copper Zinc Manganese ].evel o0 o.... O o o...0 Std. Dev. ii / Two to four samples represented by each production source for a total of 0 samples. All values expressed on a dry matter basis. All values in the same column not covered by the same line are significantly (P <.0) different. / Within production source standard deviation.

6 0 FLORIDA STATE HORTICULTURAL SOCIETY, ether extract,.0%; crude fiber,.%; and nitrogenfree extract, 0.0 %. Significant (P<.0) differences in the levels of all nutrients were found among production sources. Mineral composition of citrus pulp samples collected dur ing and the first quarter of was de termined. The average composition of macro minerals expressed on a dry matter basis was as follows: calcium,.%; magnesium, 0.%; phosphorus, 0.%; potassium,.0%; sodium, 0.%; and sulfur 0.0%. The average levels of the micro minerals expressed on a similar basis were as follows: iron,. ppm; copper,. ppm; zinc,. ppm; and manganese,.0 ppm. Acknowledgments The authors wish to acknowledge the Florida Citrus Processors Association in cooperation with the Florida Citrus Commission for funds in support of this study; Mrs. Mary Maud Sharpe, Chief, Feed Laboratory, Division of Chemistry, Florida Department of Agriculture for the proximate analyses of citrus pulp sam ples and for supplying samples of pulp for min eral analyses; and Barbara King for technical assistance. LITERATURE CITED. Anonymous.. Analytical Methods for Atomic Absorption Spectrophotometry. PerkinElmer Corp., Norwalk, Connecticut.. Ammerman, C. B., J. F. Easley, L. R. Arrington and F. G. Martin.. Factors Affecting: the Physical and Nutrient Composition of Dried Citrus Pulp. Proc. Fla. State Hort. Soc. :.. Association of Official Agricultural Chemists. Official Methods of Analysis. th Ed. Washington, D. C. 0.. Bartlett, G. R.. Phosphorous Assay in Column Chromatography. J. Biol. Chem. :.. Duncan, D. B.. Multiple range and multiple F. tests. Biometrics :.. Hendrickson, R. and J. W. Kesterson.. By Products of Florida CitrusComposition, Technology, and Utilization. Fla. Agr. Exp. Sta. Bui... Kirk, W. G. and G. K. Davis.. Citrus products for beef cattle. Fla. Agr. Exp. Sta. Bui... Marston, H. R. and D. W. Dewey. 0. The estima tion of cobalt in plant and animal tissues. Australian J. Exptl. Biol. Med. Sci. :.. Parker, H. E.. Magnesium, calcium, and zinc in animal nutrition. PerkinElmer Atomic Absorption News letter. :.