Buffalo Bulletin Vol. 22 No.1 (March 2003 ) p.12-15




A. Ramesh Babu, D. Srinivasa Rao and M.Parthasarathy


Department of Animal Nutrition, College of Veterinary Science, Tirupati 517 502, (Andhra Pradesh), India




    Papaya (Carica papaya) pomace was evaluated in sacco using four rumen fistulated  buffaloes (280 ± 2.0 kg b.wt) fed 1.35 kg of concentrate mixture (containing 30% papaya pomace) and 4.5 kg rice straw daily. The average in sacco DM disappearance values were 26.69, 43.50, 67.77, 75.98 and 82.26% at 6, 12, 24, 48 and 72 h incubation, respectively, and the average CP disappearance values were 27.82, 41.25, 46.02, 57.60 and 65.20 % at 3, 6, 9, 15 and 24 h incubation, repectively. The readily soluble fraction (a), insoluble but degradable fraction (b) and rate constant / h (c) were 14.54, 13.74; 68.88, 56.20 and 0.0528, 0.1014, respectively for DM and protein fractions of papaya pomace. The effective degradability of DM was 49.9% and protein was 51.4% for papaya pomace. RDP and UDP contents of papaya pomace were 51.4 and 48.6 g per 100 g of protein.


    Papaya (Carica papaya) pomace is a fruit by-product obtained after extraction of juice from the papaya fruit and comprises peels (skins) and seeds. Generally this goes as a waste causing  environmental pollution, but if utilized properly will contribute to the national economy and reduce environmental pollution. An attempt was made to determine the chemical composition and the degradability of locally available papaya pomace.



    Papaya pomace was obtained from local fruit juice factory and analysed for proximate constituents (AOAC, 1995) and cell wall constituents (Goering and Van Soest, 1970). Four native male buffaloes of 7 years age (280 ± 2.0 kg) fitted with a rumen fistula (Bar Diamond, Inc., USA) used for this study were daily fed 1.35 kg concentrate mixture (27% maize, 24% de-oiled groundnut cake, 17% de-oiled ricebran, 30% papaya pomace and 2% mineral mixture) and 4.5 kg of rice straw at 8.00AM to meet the nutrient requirements for maintenance (Kearl, 1982). In sacco studies were conducted according to the methods of Orskov et al. (1980) to study the rumen degradability of DM and CP of papaya pomace after a preliminary feeding period of 14 days.


    Ground papaya pomace was sieved through British Standard Sieve (BSS) mesh No. 100 to remove particles smaller than 150 m. The  polyester bags used were of 16 x 7 cm. size with a specified pore size of 44 µm and 33% of the cloth surface open (estal mono, code ASTM 325-44). A 3 g sample of papaya pomace along with a glass marble was kept in the polyester bags, which were wetted in water to escape any lag time for microbial attachment. The bags was manually pushed deep into the liquid phase of ventral sac of the rumen. About 90 cm polypropylene thread was used so that there would be a length of about 60 cm for free movement of the bag inside the rumen. Eight bags on each buffalo were incubated for time intervals of 3, 6, 9, 12, 15, 24, 48, 72 h. On removal from the rumen at specified intervals the bags were washed under tap water to remove rumen fluid from the bags surface. Bags were dried to constant weight for 48 h in a forced draft oven at 60 ° C. The in sacco DM and CP disappearance was estimated.


    The constants a, b and c of the Orskov and McDonald (1979) model were derived by iterative least square analysis with the aid of a computer. An outflow rate (K) value of 0.04 / h was used to calculate the effective degradability values.



    The chemical composition of papaya pomace observed in the present study was 92.20, 18.44, 4.73, 29.58, 28.59, 18.66, 1.84 and 0.61 % for DM, CP, EE, CF, NFE, total ash, calcium and phosphorous, respectively (Table 1). Not much literature is available on the chemical composition of papaya pomace. However, Fouzder et al. (1999) reported that dried papaya skins contained 87.41 % DM, 22.90% CP, 36.80% EE, 12.20% CF, 49.78% NFE and 11.44%  total ash.


    Forty-four percent of DM had disappeared by 12 h incubation and a further 32.5% by the end of 48 h (Table 2). In general, DM disappearance of papaya pomace linearly increased as its incubation period in rumen increased. The instantly soluble DM fraction (a) of papaya pomace was 14.54 and that of insoluble but degradable fraction with time (b) was 68.88 with a rate constant (c) of 0.0528, the effective DM degradability was 49.9 %. In a study with apple pomace, Singh and Narang (1992) reported values of 18.9, 68.8 and 83.5% respectively for a, b and 48h digestibility of DM in cattle.


There was also a linear increase in the protein disappearance of papaya pomace with increase in the period of incubation in the rumen to 24 h. Twenty- seven percent  of the protein had disappeared by 3 h of its incubation and a further 37 % by the end of 24 h incubation. The a and b fractions of papaya pomace were 13.74 and 56.20%, respectively, with a rate constant of 0.1014. The effective protein degradability was 51.4%. The RDP and UDP contents of papaya pomace were 51.4 and 48.6 g per 100 g of protein.


    It is concluded that papaya pomace with  effective degradability of DM and CP up to 49.9 and 51.4%, respectively is a  fruit by-product with potential as a feedstuff.. 


Table 1. Chemical composition (%DM basis) of papaya pomace.


                         Parameter                                                                                                                                 %


                       Dry matter                                                                                           92.20


                       Crude protein                                                                                     18.44


                       Ether extract                                                                                         4.73


                       Crude fibre                                                                                          29.58


                       Nitrogen free extract                                                                         28.59


                       Total ash                                                                                             18.66


                       Acid insoluble ash                                                                              4.04


                       Calcium                                                                                                 1.81


                       Phosphorus                                                                                          0.61


                             Cell wall constituents


                       Neutral detergent fibre                                                                     42.05


                       Acid detergent fibre                                                                          37.07


                       Hemicellulose                                                                                       4.98


                       Cellulose                                                                                             30.37


                       Acid detergent lignin (ADL)                                                             6.70





Table 2.  Effect of rumen environment on in sacco DM and protein degradability (%) of papaya pomace.



      Incubation period         DM disappearance                Incubation period                CP disappearance


                6 h                             26.69    ±     1.41                          3 h                                       27.82   ±      2.00


                12 h                           43.50    ±     2.32                          6 h                                       41.25   ±      1.94


                24 h                           67.77    ±     2.22                          9 h                                       46.02   ±      1.18


                48 h                           75.98    ±       1.07                          15 h                                     57.60   ±      3.83


                72 h                           82.26    ±     0.75                          24 h                                     65.20   ±      3.71


      Degradation kinetics


                A                               14.54                                                                                        13.74


                B                               68.88                                                                                        56.20


                C                                 0.0528                                                                                      0.1014


                A+b                          83.42                                                                                        69.94


                ED%                         49.9                                                                                          51.4


RDP 51.4 g and UDP 48.6 g per 100 g protein of papaya pomace.




AOAC (1995). Official Methods of Analysis (16th Ed.) Association of Official Analytical.      Chemists, Washington, DC.

Goering, H.K. and P.J. Van Soest (1970). Forage Fibre Analysis (Apparatus, reagents,            procedures and some applications) ARS, USDA Agricultural Hand Book No. 379, Washington, DC.

Kearl, L.C. (1982). Nutrient requirements of ruminants in developing countries. International Feedstuffs Institute, Utah Agricultural Experimental Station, Utah State University, Logan, Utah, USA.

Orskov, E.R.,  F.D. Hovell, and F. Mould (1980). The use of nylon bag technique for the evaluation of feedstudffs. Trop. Anim. Prod. 5: 195.

Orskov, E.R. and I. McDonald (1979). The estimation of protein degradability in the rumen from  incubation measurements weighed according to rate of passage. J. Agric. Sci. Camb., 92: 499.

Fouzder, S.K., S.D. Chowdhary, M.A.R. Howlider, and C.K. Podder  (1999). Use of dried papaya skins in the diet of growing pullets. British Poultry Science.  40: 88.

Singh, B. and M.P. Narang (1992). Studies on the rumen degradation kinetics and utilization of apple pomace. Bioresource-Technology   Publication. 39: 233.