Use of Papain and Bromelain in theProduction of Oyster Sauce

Pranisa Chuapoehuk and Nongnuch Raksakulthai

ABSTRACT MATERIALS AND METHODS

Minced oyster meat samples were hydrolyzed using papain The materials used were shucked cultured oyster,or bromelain at concentrations of 0, 0.1, 0.3, 0.5 and 0.7% (Crassostrea sp.) from Tambon Angsila, Amphur(w/w). Each sample was supplemented with 20% sodium Muang, Chonburi Province, Thailand; Papain enzymechloride. It was found that 0.7% papain or 0.3% bromelain prepared by Kunkriangwong (1988) from papaya fruityieldedthehighestsolublenitrogenin thehydrolysates. Oyster of Khagdam strain with protease activity of 30,000sauces prepared from 0.7% papain or 0.3% bromelain units per gram; and Bromelain enzyme (No. 083 BML)hydrolysates supplemented with 20% sodium chloride showed from Great Food Co., Bangkok, Thailand.no significant differences in proximate composition, pH,consistency,andsensoryevaluationscores.Chinese watercress Nine commercial oyster sauce samples were eachstir-fried with these prepared oyster sauces received higher analyzed for protein, lipid, ash, moisture, carbohydrateacceptabilityscores than commercial oyster sauce (p

mended by the Department of Science Services (1976) Table 1. Proximate composition, consistency and pHand jittinun and Saelim (1985), as follows: of commercial oyster sauce'

Hydrolysate 60g SampleTotalN Protein Fat Moisture Ash Carbohydrate NaCl Consis pH

S 2 0glKg %% % % % %tency

oy sauce g (cm/min)Sugar 7g

Glucose 109 1 1.5 0.9 0.8 76.8 8.5 13.4 7.5 1.1 5.1

Sodium succinate 19 2 2.6 1.6 1.3 73.5 6.6 18.1 7.8 1.3 5.1

Succinic acid 0.3g

Monosodium glutamate 2.7g 3 4.4 2.7 0.4 69.0 8.7 19.5 6.9 0.8 5.2

Modified corn starch 5g 4 4.7 2.9 1.0 62.5 12.5 15.1 12.3 1.3 5.1Water 20g

5 4.8 3.0 0.9 60.5 10.5 25.5 10.4 1.4 5.0

This mixture was thoroughly mixed and boiled for 2 6 4.9 3.1 1.9 76.6 6.4 13.7 4.5 0.7 5.6minutes to produce the prepared oyster sauces.

7 6.8 4.3 0.4 57.9 13.0 24.8 12.2 0.9 5.7

The prepared oyster sauces were ana lysed and evalu- 8 7.1 4.4 0.7 82.1 6.3 8.8 4.5 1.2 5.5ated in the same way as the commercial oyster sauces.To compare acceptability, the prepared oyster sauces 9 7.4 4.6 1.0 82.3 6.2 6.8 4.5 1.2 5.4and the most acceptable commercial oyster sauce sam-ples were used as a condiment in stir-fried Chinese lValues are averages of three determinations.watercress. The stir-fried watercress samples wereevaluated by 10 panelists. At the present time there is no official standard for

oyster sauce. These analyses of protein content inStorage Life of Prepared Oyster Sauces commercial oyster sauce (Table 1) could be used as a

basis for requiring a 3% protein content in preparedThe prepared oyster sauces were stored at room oyster sauce, since the average protein content is 3.07%temperature (about 30°C) in 50mL glass bottles withscrew caps for 12 weeks. The sauces were checked every The pH of commercial oyster sauces (Table 1) ranged2 days for mould development. from 5.0 to 5.7, which agreed with the 5-6 range set

by TISI (1983) for fish sauce. The consistency values

RESULTS AND DISCUSSION ranged from 0.7-1.4 em per minute. Consistency of thesauce should be related to the amount of starch or

Commercial Oyster Sauces othercarbohydrateadded,howevertheregressionanalysisof the carbohydrate content and consistency shows no

The proximate composition of commercial oyster sauce correlation (r'=0.008).samples (Table 1) varied greatly. The average proteincontent was 3.1 %. It has been reported that protein Table 2 shows significant differences (P

Six samples were not significantly different in colour Table 3. Proximate composition, consistency and pH(5.9 - 7.1), but the remaining three samples received of prepared oyster sauce'unacceptably lower scores (3.7 - 4.9). Eight samplesshowed nonsignificantly different scores (4.8 - 6.2) for Enzyme Protein Fat Moisture Ash CHO NaCl Consis pHodeuy but were significantly different from the % % % % % % teney

I . . d f 2 3 F.

IIcm/minlsarnp e receIvIng an 0 our score 0 .. lye samp es

were not significantly different in flavour scores (5.5 Papain

- 6.9) but were significantly different to samples re- 0.7% 4.9 0.2 63.8 14.2 16.9 14.6 0.8 5.0ceiving scores of 5.4 or lower.

B .romelam0.3% 5.1 0.8 65.1 13.7 16.9 13.5 0.8 5.0

Commercial oyster sauce samples receiving high sen- .sory evaluation scores were brown in colour, smooth 1 Values are average of duplicate determination of threein texture, not too thick and had a sme]] of boiled replicates.oyster, while samples receiving low scores were lighterin colour, had a salty taste and very mild odour.

found in the samples treated with papain, leaving less

P d 0 t S fat in the liquid Part. Protein values of Pre pared Oysterrepare ys er aucessauces were higher than those of commercial sauces.

Figure 1 shows the effect of concentration of papain However, the pH and consistency of prepared andor brornelain, on total nitrogen in oyster hydrolyzates. commercial sauces were similar.Papain at 0.7% and bromelain at 0.3% by weight ofoyster meat yielded the highest total nitrogen contents. The colour, odour and flavour of the two preparedFrom 100g of oyster meat, papain and bromelain sauces were not significantly different. The total sensoryyielded 50 and 60mL of hydrolyzate, respectively. evaluation scores of the prepared sauces were higher

than those of the commercial sauces.

Table 4 shows the overall preference scores of stir-fried7.0Chinese watercress with prepared and commercial

Legend 0 papain sauces. The average preference score of the sauce6.0 6 bromelain prepared from papain was higher but not statistically

different from that of the sauce prepared from5.0 bromelain. The preference scores of the prepared

::? sauces were, nevertheless, higher (p ,;;0.05) than those:9 4.0 of the commercial sauces.~

"'"~ 3.0 Table 4. Sensory evaluation scores of prepared and(tj commercial oyster sauces and acceptability

~ scores of stir-fried Chinese watercress with2.0 different oyster sauces.

1.0 Sensory scores AcceptabilityColour Odour Flavour scores

Prepared sauce 7.1a 6.5a 6.5a 7.7a0.1 0.2 0.3 0.4 0.5 0.6 0.7 using papain 0.7%

Cone. of enzyme (%)

Prepared sauce 6.7a 5.3a 6.4a 7.4a. . using bromelainFIg. 1 Effect of enzyme concentratIOns on the total

03%nitrogen content of oyster hydrolyzate. Values' 0

plotted are averages of three determinations.B

. I 6 7 6 2 6 9 5 9best commerCia . a . a . a .oyster sauce

The proximate composition, consistency, pH, and sen- Values are averages of 11 panelists; values in the samesory evaluation scores of prepared oyster sauces are c~lumn followed by the same letter are not significantlypresented in Table 3. The protein, moisture, ash, car- d1fferent (p ,;; 0.05)

bohydrate and sodium chloride content of sauces preparedfrom papain or bromelain were not significantly dif- There was no development of mould in the preparedferent but the fat content of the sauce prepared with sauces kept at room temperature in glass bottles withpapain was much lower than in the sauce prepared with screw caps for 12 weeks, indicating that the sauces canbromelain(Table3). This is perhaps due to more residue be stored under such conditions for at least 12 weeks.

198 ASEAN Food Journal Vol. 7, f\lo. 4, 1992

Food198

FoodASEAN Food Journal Vol. 7, f\lo. 4, 1992

ACKNOWLEDGEMENT Kunkriangwong, J. Use of papaya milk and papainto improve qualityofbeeffrom old cow. (In Thai).

Grateful acknowledgement is due to the National Kasetsart University, 1988. M.5 Thesis.Research Council of Thailand for providing the nec-essary financial assistance. Larmond, E. Laboratory methods for sensory

evaluation of food. Research Branch, Dept. ofRFERENCES Agriculture, Canada. Publication 1937. 1977.

AOAC. Official Methods of Analysis 13th ed. Wash- Raksakulthai, N., Lee Y.Z. and Haard N.F. Effect ofington D.C.: Association of Official Analytical enzyme supplements on the production of fishChemists, 1980. sauce from male capelin (Mallotus vi1losus). Can.

Inst. Food Sci. Techno!. J. 19: 28-33; 1986.Department of Science Services. Oyster sauces. Ministry

of Science and Technology. 102-105 (In Thai). 1976. Thai Industrial Standards Institute (TIS!). Specificationsfor flavouring sauce. Bangkok: Ministry of In-

Department of Customs. Foreign Trade Statistics of dustry, 1970. (In Thai).Thailand. Bangkok. 1987.

TIS!. Standard for local fish sauce. Bangkok: MinistryICMSF. Microorganisms in food. 1: The significance of Industry, 1983. (In Thai).

and methods of enumeration. 2nd ed. Toronto:University of Toronto, 1987. TIS!. Standard for soy sauce. Bangkok: Ministry of

Industry, 1987. (In Thai).Jittinun, S. and Saelim, J. Development of mollusc sauce

products. Dept. of Food Science and Technology,Chulalongkorn University. (In Thai). 1985.

Kirimura, L Shimizu A., Kimizuka K., Ninomiya T. andKatsuya N. Contribution of peptides and aminoacids to the taste of foodstuffs. J. Agric. FoodChern. 17: 689-695; 1969.

ASEAN Food Journal Vol. 7, No.4, 1992 199

FoodASEAN Food Journal Vol. 7, No.4, 1992 199

page 1TitlesABSTRACT MATERIALS AND METHODS Customs, 1987). Optimal Concentration of Enzymes in Preparation of ... . . concentration of enzyme to produce the highest total scores of oyster sauces produced by the use of papain . - 196 ASEAN Food Journal Vol. 7, No.4, 1992

page 2TitlesHydrolysate 60g Sample Total N Protein Fat Moisture Ash Carbohydrate NaCl Consis pH Sugar 7g Succinic acid 0.3g Water 20g minutes to produce the prepared oyster sauces. ated in the same way as the commercial oyster sauces. Commercial Oyster Sauces othercarbohydrateadded,howevertheregressionanalysis ASEAN Food Journal Vol. 7, No.4, 1992 197

page 3Titles. . were not significantly different in flavour scores (5.5 Papain 0.3% 5.1 0.8 65.1 13.7 16.9 13.5 0.8 5.0 in texture, not too thick and had a sme]] of boiled replicates. fat in the li uid art. Protein values of re ared O ~ 3.0 Table 4. Sensory evaluation scores of prepared and 1.0 Sensory scores Acceptability 0.1 0.2 0.3 0.4 0.5 0.6 0.7 using papain 0.7% FIg. 1 Effect of enzyme concentratIOns on the total 03% 9b est commerCia . a . a . a . 198 ASEAN Food Journal Vol. 7, f\lo. 4, 1992

page 4TitlesACKNOWLEDGEMENT Kunkriangwong, J. Use of papaya milk and papain essary financial assistance. Larmond, E. Laboratory methods for sensory ASEAN Food Journal Vol. 7, No.4, 1992 199