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

Department of Animal Nutrition, College of Veterinary Science

Tirupati – 517 502, (Andhra Pradesh), India

ABSTRACT

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, respectively. 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 and protein fractions of papaya pomace. The effective degradability of 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.

INTRODUCTION

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

MATERIALS AND METHODS

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 yrs 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 mm . The polyester bags used were of 16 x 7 cm. size with a specified pore size of 44 mm 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 were manually pushed deep into the liquid phase of ventral sac of the rumen. About 90 cm polypropylene thread was used to have about 60 cm length of it for free movement of the bag inside the rumen. Eight bags on each buffalo were incubated at time intervals of 3, 6, 9, 12, 15, 24, 48, 72 hrs. On removal from the rumen at specified intervals the bags were washed under tap water to remove rumen fluid from the bag’s 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 Orskov and Mc Donald (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.

RESULTS AND DISCUSSION

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 per cent of DM disappeared up to 12 h incubation and 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 with time (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 and 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 24h. Twenty seven per cent protein disappeared by 3 h of its incubation and further 37% by and 56.20% respectively with a rate constant of 0.1014. The effective protein degradability was 51.4%. The RDP and UDP contents of paraya pomace were 51.4%. The RDP and UDP contents of papaya pomace were 51.4 and 48.6 g per 100g of protein.

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

Table1. 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	1.84
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 cacco DM and Protein

degradability (%) of papaya pomace

Incubation period	DM disappearance	Incubation period	CP disappearance
6h	26.69+-1.41	3h	27.82+-2.00
12h	43.50+-2.32	6h	41.25+-1.94
24h	67.77+-2.22	9h	46.02+-3.83
48h	75.98+-1.07	15h	57.60+-3.83
72h	82.26+-0.75	24h	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 51.4g and UDP 48.6 g per 100g protein of papaya pomace.

REFERENCES

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

GOERING, H.K. and VAN SOEST, P.J. (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, Utha State University, Logan, Utah, USA.

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

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

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