Jananese Journal of Lactic Acid Bacteria Vol.10, No. 1 Copyright © 1999, Japan Society for Lactic Acid Bacteria 総 説 Microorganisms and Technology of Philippine Fermented Foods Priscilla C. SANCHEZ Institute of Food Science and Technology College of Agriculture, University of the Philippine-Los Banos College, Laguna 4031, Philippines INTRODUCTION Technological advances that were made elucidated Fermented foods are essential components of the role of microorganism on the physical and diets in many parts of the world especially in the chemical changes that occurred in the processed raw Asia. It is a highly acceptable form of food preser- materials. Microbial interactions during fermenta- vation for millions of consumers due to its nutri- tion were affected by the existing environmental tive value and wholesome flavor. conditions and were found to influence the produc- The methods of processing traditional fermented tion and the wholesomeness of the products. Se- foods were developed in households and improve- lected strains were employed in the process of ments were done as the process is handled down improvement and standardization into the stable from one generation to another. Mostly of these and high quality products and processes that are processes were developed on a trial and error basis, routinely used. hence quality varied from one maker to the other. In the Philippines, there are quite a number of BACTERIAL FERMENTED FOODS traditional fermented foods such as rice wine (tapuy) , sweetened rice (binubudan) , fermented rice WHITE SOFT CHEESE (Kesong Puti) cake (puto) , fermented cooked rice and shrimp Kesong puti is a traditional cheese made from (balao-balao) , fermented cooked rice and fish fresh cow's or carabao's milk using rennet and lac- (burong isda) , sugarcane wine (basi) , coconut wine tic acid bacteria. It is prepared in rural households (tuba) , distilled coconut wine (lambanog) , palm and normally consumed right after its preparation. sap vinegar (suka) ,fermented fish paste (bagoong) , The product is characterized as a mild acid-type fermented fish sauce (patis) , fermented small soft cheese which is white in color. It is usually shrimp (alamang) ,Visayan fermented fish (tinabal) , wrapped in fresh banana leaves hence its shelf-life green papaya pickles (achara) , fermented mustard is short at ambient temperature (28-30 °C ) and leaves (burong mustasa) , green mango pickles about one week at 5°C storage. (burong mangga) , white soft cheese (kesong puti) , Kesong puti is a nutritious product due to its and nata, a pellicle produced by Acetobacter high protein content (23%), high amount of food xylinum on coconut medium (water or milk) fruit energy (297calories) , calcium (323mg%) , phosphorous juices and other sugar-rich raw materials. (166mg%) and trace amount of vitamins and min- erals. It has a pH of 5.50, total titrable acidity of *Paper presented at the "International Symposium 0.25% (expressed as % lactic acid), and 2.5% salt. on Traditional Fermented Foods Microbial Tech- Preparation of Kesong Puti nology and Ecology", August Pt, 1998, Hokkaido The collected fresh milk is strained and volume University, Sapporo, Japan. determined. Rennet is added and the mixture is — 19 — Vol.10, No. 1 Japanese Journal of Lactic Acid Bacteria stirred thoroughly and allowed to curdle for one consisted of washing of the live shrimp (Penaeus half to one hour. When complete coagulation is at- indicus or Macrobrachium spp.), adding salt (20% tained, the curd is scooped into a perforated basin based on the shrimp weight) , allowing to stand for to drain the whey. The slightly drained curd is 2 hours before draining the mixture. Cooked cooled poured into a container, salted, macerated and rice is then mixed with the shrimps at the ratio of beaten until smooth. The slurry is poured into the 1 : 4.8 (weight of unsalted shrimp to rice). Salt cheese molds where it is left to drain further by ( 3 %) is mixed thoroughly before the mixture is gravity. As a final step, the firm curd is cut and packed in wide mouth glass jars. The mixture is al- wrapped in banana leaves or plastic sheet. lowed to ferment for 7 to 10 days at 28°C. Microorganisms in Kesong Puti Fermentation Microorganisms in Balao-balao Fermentation After 24 hours of fermentation, different species The Fermentation of balao-balao is carried out in of bacteria (belonging to Lactobacillus, Streptococ- a sequential manner whereby the first stage (up to cus, Flavobacterium, Achromobacter, Pseudomonas, 4 days) is dominated by cocci belonging to Serratia, Micrococcus and Aerobacter) and yeasts Leuconostoc mesenteroides which plays a major role (Torula spp.) were isolated. As fermentation pro- in the acid production. On the fifth day the flora is gressed, the lactic acid bacteria such as Streptococ- dominated by Pediococcus cerevisiae and then cus lactis, S. cremoris, S. diacetylactis and shifted to Lactobacillus plantarum on the seventh Lactobacillus casei predominated and replaced the day of fermentation. The changes of dominant other microorganisms. flora during fermentation is overlapping which sug- Process Improvement gest that there was a change of conditions during The traditional method of manufacture of kesong the fermentation process that led to the death of puti was improved by pasteurizing the milk, addi- one species and the enhancement of the other. tion of rennet and lactic acid starter culture con- sisting of S. lactis, S. cremoris, and S. diacety- FERMENTED FISH-COOKED RICE MIXTURE lactis, either singly or in combination and addition (Burong lsda) of salt to the cheese milk for even distribution. Burong isda is a popular traditional food in the Proper sanitation practices were also observed. A central part of Luzon particularly in Pampanga, better keeping quality product with the characteris- Bulacan, Cavite and Nueva Ecija. Different varia- tic flavor, texture and body was obtained with the tions of the product are made by using different new process. species of fish such as Ophicephalus striatus (burong dalag) , Tilapia plumbeus (burong tilapia) , Chanos FERMENTED SHRIMP-COOKED RICE MIXTURE chanos (burong bangus) , Therapon plumbeus (burong (Balao-balao) ayungin) with or without addition of red rice or Balao-balao is a traditional food consumed as a angkak (produced by growing Monascus purpureus sauce or main dish after sauteing in vegetable oil on cooked rice). The product is consumed as a sauce with garlic and onion. The product is acidic with or as main dish after sauteing in vegetable oil with free-flowing consistency where the shell of the garlic and onion. Similar products are produced in shrimp becomes red and soft and the rice starch is other Southeast Asian countries like phaak or saccharified. A similar product in Thailand is manchao in Cambodia, pla-ra in Thailand, pekasam known as kung chao or hung sam (Vatana, 1982). and cencalok in Malaysia, sikhae in Korea and Changes in acidity during fermentation at 28°C narezushi in Japan (Johari, 1978; Lee, et al., 1977). showed that from zero time to 10 days, pH de- Preparation of Burong Isda creased from 7.52 to 3.80, titrable acidity (as lac- Fresh water fish is used in the preparation of tic acid) increased from 0.12 to 2.0% and volatile burong isda. The fish is scaled, gills and fins are acid (as acetic acid) increased from 0.03 to 0.1%. removed, then it is splitted into butterfly fillet. Preparation of Balao-balao After thoroughly washing the fish, it is packed al- The general method of preparation of balao-balao ternately with a mixture of cooked rice and 2.5% — 20 — Japanese Journal of Lactic Acid Bacteria Vol.10, No. 1 salt at the ratio of 35 : 65 (salted cooked rice : products are the nuoc-mam in Cambodia and fish). Fermentation is carried out for 7 days at Vietnum, yu-hu in China, shottsuru in Japan, budu 28°C to 30°C. in Malaysia, jeot-kuk in Korea, nam-pla in Thai- Microorganisms in Burong lsda Fermentation land and Laos, ketjap-ikan in Indonesia and ngan- Sequential changes of the bacterial flora occurred pya-ye in Burma (Johari, 1978,; Lee, et al., 1977). during burong isda fermentation wherein the domi- Preparation of Bagoong and Patis nant flora were Bacillus subtilis, B. cereus, Lacto- The common type of fish employed are dilis bacillus brevis, Streptococcus faecalis. Leuconostoc (Stolephorous spp.) , tamban (Sardinella fimbriata), mesenteroides, Pediococcus cerevisiae, L. fermentum galonggong (Decapterus spp.). The fish is washed and L. plantarum. thoroughly and drained. Salt is mixed with the During the fermentation process, starch hydroly- drained fish at varying proportion from 1 : 3 to 2 sis occurred favoring the growth of the low acid : 7 (salt : fish) depending on its size. The mixture tolerant lactic acid bacteria that later shifted to is allowed to ferment in a warm (40°C) place for high acid tolerant lactic acid species. The activities several months or longer until it develops the char- of these microorganisms are influenced by the envi- acteristic flavor and aroma of the product. Usu- ronmental conditions operating in the system. ally the preparation of patis takes a longer time Process Improvement than that of bagoong. The process of preparation of burong isda was The chemical composition of six-month old patis improved by addition of starter culture consisting showed that it has a pH of 5.85, 26.10% sodium of the dominant microorganisms isolated from the chloride, 2.26% total nitrogen, 1.31% formol nitro- traditional method such as Pediococcus acetilactici gen, 0.31% ammonia nitrogen, 1.0% amino nitrogen and Leuconostoc mesenteroides. The process was and 0.84% lactic acid content. Patis contained 15 shortened to 4 days and the product is of better amino acids with no cystine and proline. The domi- quality. nant amino acids are lysine (1083mg%), histidine (976mg%) and glutamic acid (960mg%).