Showing papers in "Food Technology and Biotechnology in 2006"

Biotechnological Production of Lactic Acid and Its Recent Applications

Abstract: Summary Lactic acid is widely used in the food, cosmetic, pharmaceutical, and chemical industries and has received increased attention for use as a monomer for the production of biodegradable poly(lactic acid). It can be produced by either biotechnological fermentation or chemical synthesis, but the former route has received considerable interest recently, due to environmental concerns and the limited nature of petrochemical feedstocks. There have been various attempts to produce lactic acid efficiently from inexpensive raw materials. We present a review of lactic acid-producing microorganisms, raw materials for lactic acid production, fermentation approaches for lactic acid production, and various applications of lactic acid, with a particular focus on recent investigations. In addition, the future potentials and economic impacts of lactic acid are discussed.

Gluconic Acid: Properties, Applications and Microbial Production

Abstract: Summary Gluconic acid is a mild organic acid derived from glucose by a simple oxidation reaction. The reaction is facilitated by the enzyme glucose oxidase (fungi) and glucose dehydrogenase (bacteria such as Gluconobacter). Microbial production of gluconic acid is the preferred method and it dates back to several decades. The most studied and widely used fermentation process involves the fungus Aspergillus niger. Gluconic acid and its derivatives, the principal being sodium gluconate, have wide applications in food and pharmaceutical industry. This article gives a review of microbial gluconic acid production, its properties and applications.

New perspectives for citric acid production and application

Abstract: There is a great worldwide demand for citric acid consumption due to its low toxicity when compared with other acidulants used mainly in the pharmaceutical and food industries. Other applications of citric acid can be found in detergents and cleaning products, cosmetics and toiletries, and other. Global production has now reached 1.4 million tonnes and there is annual growth of 3.5–4.0 % in demand/consumption of citric acid. As a result of the adverse market conditions, only big producers have survived. Any increase in citric acid productivity would be of potential interest and hence there is an obvious need to consider all possible ways in which this might be achieved. The production by submerged fermentation is still dominating. However, solid-state processes can create new possibilities for producers. Many by-products and residues of the agro-industry can be used in the production of citric acid. A cost reduction in citric acid production can be achieved by using less expensive substrates. The use of agro-industrial residues as support in solid-state fermentation is economically important and minimizes environmental problems. Other perspectives for citric acid production sector are the improvement of citric acid producing strains, which have been carried out by mutagenesis and selection.

Phytase for food application

Abstract: Phytase [myo-inositol(1,2,3,4,5,6)hexakisphosphate phosphohydrolase], a phytate-specific phosphatase, is already used as a supplement in diets for monogastric animals to improve phosphate utilisation from phytate [myo-inositol(1,2,3,4,5,6)hexakisphosphate], the major storage form of phosphate in plant seeds. In recent years, this class of enzymes has also been found increasingly interesting for use in processing and manufacturing of food for human consumption, particularly because the decline in food phytate results in an enhancement of mineral bioavailability. Different strategies could be applied to optimise phytate degradation during food processing and digestion in the human alimentary tract such as adjustment of more favourable conditions during food processing for the phytases naturally occurring in the raw material, addition of isolated phytases to the production process, use of raw material with a high intrinsic phytate-degrading activity either naturally present or introduced by genetic engineering and the use of recombinant food-grade microorganisms as carriers for phytate-degrading activity in the human gastrointestinal tract. Furthermore, phytases may find application in the production of functional foods or food supplements with health benefits. Last but not least, technological improvements are expected to occur due to phytate degradation during processing as shown for breadmaking, production of plant protein isolates, corn wet milling and the fractionation of cereal bran.

Production of Food Aroma Compounds: Microbial and Enzymatic Methodologies

Abstract: Summary Over the past few years, the increasing demand for natural products in the food industry has encouraged remarkable efforts towards the development of biotechnological processes for the production of flavour compounds. The present paper reviews the recent major achievements reported in this field, with a special emphasis on the potential lying in plant cell, microbial cultures and enzyme technology for the production of a wide range of flavours. The use of solid-state fermentation as a means to improve economical feasibility of these processes is also considered.

Microbial Production of Food Grade Pigments

Abstract: Summary The controversial topic of synthetic dyes in food has been discussed for many years. The scrutiny and negative assessment of synthetic food dyes by the modern consumer have raised a strong interest in natural colouring alternatives. Nature is rich in colours (minerals, plants, microalgae, etc.), and pigment-producing microorganisms (fungi, yeasts, bacteria) are quite common. Among the molecules produced by microorganisms are carotenoids, melanins, flavins, quinones, and more specifically monascins, violacein or indigo. The success of any pigment produced by fermentation depends upon its acceptability on the market, regulatory approval, and the size of the capital investment required to bring the product to market. A few years ago, some expressed doubts about the successful commercialization of fermentation-derived food grade pigments because of the high capital investment requirements for fermentation facilities and the extensive and lengthy toxicity studies required by regulatory agencies. Public perception of biotechnology-derived products also had to be taken into account. Nowadays some fermentative food grade pigments are on the market: Monascus pigments, astaxanthin from Xanthophyllomyces dendrorhous, Arpink Red from Penicillium oxalicum, riboflavin from Ashbya gossypii, b-carotene from Blakeslea trispora. The successful marketing of pigments derived from algae or extracted from plants, both as a food colour and a nutritional supplement, reflects the presence and importance of niche markets in which consumers are willing to pay a premium for »all natural ingredients«.

Microbiology and Industrial Biotechnology of Food-Grade Proteases: A Perspective

Abstract: Summary Recent developments in industrial biotechnology have resulted in the exploitation ofnew and undiscovered microorganisms and the devising of improved methods for en-zyme production, which have led to increased yields of the enzyme, thus making a viableindustrial process feasible. This review tracks the developments in the field of acidic andneutral protease production with regard to the producers, methods of production andtheir improvement, the product and its applications. Key words : neutral protease, acidic protease, fermentation, genetic engineering, purifica-tion, enzyme assay Introduction Proteases are one of the industrially most importantenzymes. These proteolytic (protein digesting) biocata-lysts have been in use for many centuries, at first in thedairy industry as milk-clotting agents (rennet) for themanufacture of cheese. Proteases are enzymes that cata-lyse hydrolytic reactions in which protein molecules aredegraded to peptides and amino acids. These constitutea very large and complex group of enzymes, which dif-fer in properties such as substrate specificity, active siteand catalytic mechanism, pH and temperature optima andstability profile. The specificity of proteolytic enzymes isgoverned by the nature of the amino acid and other func-tional groups (aromatic or aliphatic or sulphur-contain-ing) close to the bond being hydrolysed. Proteases arepresent in all living beings and play an important rolein normal and abnormal physiological conditions, cata-lysing various metabolic reactions (

Production of food grade yeast

Abstract: Summary Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the production of microbiology media and extracts, as well as livestock feeds. Modern scientific advances allow the isolation, construction and industrial production of new yeast strains to satisfy the specific demands of the food industry. Types of commercial food grade yeasts, industrial production processes and raw materials are highlighted. Aspects of yeast metabolism, with respect to carbohydrate utilization, nutritional aspects and recent research advances are also discussed.

Solid Culturing of Bacillus amyloliquefaciens for α-Amylase Production

Abstract: Summary Fourteen different agroresidues were screened for alpha amylase production using Bacillus amyloliquefaciens ATCC 23842. Among them, wheat bran (WB) and groundnut oil cake (GOC) in mass ratio of 1:1 was proved as the best substrate source. Supplementation with 0.01 M KH2PO4 and 1 % soluble starch enhanced the enzyme yield considerably. Maximum enzyme recovery from the solid mass was obtained when extracted with 0.1 M acetate buffer, pH=5.0. Maximum enzyme titer expressed as units per mass of dry substrate obtained was 62 470 U/g after 72 hours of fermentation at 37 °C by using the above solid substrate mixture (5 g) with the initial moisture of 85 % and inoculated with Bacillus amyloliquefaciens of 2·10 9 CFU/mL.

Production of Oligosaccharides as Promising New Food Additive Generation

Abstract: Summary Recent research in the area of carbohydrate food ingredients has shown the efficiency of oligosaccharides when they are used as prebiotics or biopreservatives Considering the former, they have various origins and structures, whereas the latter are described mostly as oligochitosans or as low molecular mass chitosans If new manufacturing biotechnologies have significantly increased the development of these functional food ingredients, the main drawback limiting their applications is the difficulty to engender specific glycosidic structures The present review focuses on the knowledge in the area of food bioactive oligosaccharides and catalogues the processes employed to generate them

Production of Extracellular Lipase from Aspergillus niger by Solid-State Fermentation

Abstract: Summary Lipase production in Aspergillus niger J-1 was tested using both submerged fermentation (SmF) and solid-state fermentation (SSF) on a mineral culture medium and wheat bran, respectively. The optimization of the culture medium was carried out for both SmF and SSF. The maximum lipase activity, 1.46 IU/mL, was obtained during the submerged fermentation in a medium containing glucose at 2 % and olive oil at 2 % under conditions of 1 vvm and 450 m –1 . However, 9.14 IU/g of dry solid substrate equivalent to 4.8 IU/mL of lipase activity was reached using solid-state fermentation process with a medium containing 0.75 % of ammonium sulphate and 0.34 % of urea. The optimum pH and temperature for enzymatic activity were pH=6 and 40 °C, respectively. The enzyme also exhibited 80 % of its initial activity in neutral and mildly acid media and at temperatures between 20 and 30 °C for a period of 24 hours.

A Simple and Rapid Determination of ATP, ADP and AMP Concentrations in Pericarp Tissue of Litchi Fruit by High Performance Liquid Chromatography

Abstract: Summary A simple and rapid method using high performance liquid chromatography (HPLC) was developed to determine levels of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) in litchi fruit pericarp tissue. This HPLC method used acetonitrile gradient elution and shortened the time required for determinations of adenosine phosphates. This analysis exhibited good repeatability (coefficients of variation 1.28–1.80 %) and recovery rate (94.7–97.1 %). The correlation coefficients of ATP, ADP and AMP with their peak areas at a range of 0–80 ng were 0.9946, 0.9994 and 0.9974, respectively. This method was applied to determine levels of adenosine phosphates in pericarp tissue of litchi fruit at harvest. There were 27.4 mg/g of ATP, 35.4 mg/g of ADP and 7.9 mg/g of AMP on a fresh mass basis.

Microbial and Processing Criteria for Production of Probiotics: A Review

Abstract: Summary The use of probiotics has become widely accepted as a natural means to promote health for both humans and animals. Today, probiotics are used as health supplements in food and feeds and they are replacing the use of antibiotic growth promotors or chemical supplements. Under the right conditions the claims made for probiotic preparations can be realized. The development of suitable technology for probiotic production, taking into account viability and stability, is a key area of research for industrial production. Production of probiotics should be based on the microbial criteria, and the ability to withstand stress during processing and storage of products is important. Thermophilic/thermotolerant probiotics are of great interest in this area as they can have all the desired characteristics. This review makes an overview of probiotic selection studies including new technologies for isolation/identification, adhesion and immune response. The importance of multistrain cultures is also stressed. The development of suitable probiotics in food and feed needs good proof of their efficacy and function in order to be accepted as a valuable product.

α-Amylase Production by Bacillus cereus MTCC 1305 Using Solid-State Fermentation

Abstract: Summary Production of a-amylase under solid-state fermentation by Bacillus cereus MTCC 1305 has been investigated using wheat bran and rice flake manufacturing waste as substrates. With wheat bran, highest enzyme production expressed as units per mass of dry substrate ((94±2) U/g) was observed. Production parameters were optimized as inoculum size 10 % (volume per mass) and substrate:moisture ratio 1:1. Among different carbon sources supplemented, glucose (0.04 g/g) showed enhanced enzyme production ((122±5) U/g). Supplementation of different nitrogen sources (0.02 g/g) showed decline in enzyme production. Optimum a-amylase enzyme activity was observed at 55 °C and pH=5. At 75 °C, enzyme showed 90 % activity compared to 55 °C.

Proizvodnja inulinaze: najnovija dostignuca

Abstract: Summary Inulinases constitute an important class of enzymes for production of fructose and fructooligosaccharides, which are extensively used in pharmaceutical and food industry. The production of inulinases has been reported from various fungal, yeast and bacterial strains. The inulinases characterized until now show considerable variability with respect to biophysical and biochemical characteristics. High temperature optimum and thermostability are two important criteria which determine the suitability of these enzymes for industrial applications. Inulinases with high thermostability from strains of Aspergillus spp. and thermophilic bacteria have been reported. Molecular cloning of inulinase genes from different sources has revealed that beside conserved domains, the endo- and exo-acting inulinases show motifs which are distinct for the two classes of enzymes. The present article reviews some of the recent advances in the production and characterization of inulinases from different microbes and their possible applications.

Degumming of Vegetable Oil by a New Microbial Lipase

Abstract: Summary Lecitase ® Ultra lipase is an acidic lipase which exhibits maximal activity at pH=5.0. It takes part in the activity towards both phospholipid and triglyceride structures. When the temperature is over 40 °C, the phospholipase activity predominates, and the lipase activity is partly suppressed. It could be applied for the degumming of vegetable oil, and the phosphatides in the oil were easily converted by enzymatic catalyzed hydrolysis to less than 10 mg/kg withi n5ha t 50°C.

Antioxidant Activity of Aqueous Tea Infusions Prepared from Oregano, Thyme and Wild Thyme

Abstract: Summary Using a multiple-method approach, antioxidant activity of aqueous tea infusions prepared from oregano (Origanum vulgare L. ssp. hirtum), thyme (Thymus vulgaris L.) and wild thyme (Thymus serpyllum L.) were tested in relation to their chemical composition. Total phenolic, flavonoid, catechin and anthocyanin content was determined by spectrophotometric methods. Oregano aqueous tea infusion had the highest amount of total phenols (12 500 mg/L gallic acid equivalent, GAE) and flavonoids (9000 mg/L GAE). Identification of polyphenolic compounds in aqueous tea infusions by HPLC-PDA analysis showed a dominant presence of rosmarinic acid (in mg/g): 123.11 in oregano, 17.45 in thyme and 93.13 in wild thyme. Antioxidant activity of aqueous tea infusions was evaluated using four antioxidative methods (the b-carotene bleaching method (BCB), the 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, the thiobarbituric acid reactive species (TBARS assay) and the induction period of lard oxidation (Rancimat assay)). The results were compared with natural (ascorbic acid and a-tocopherol) and synthetic antioxidants, butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). Oregano aqueous tea infusion showed the strongest antioxidant activity using three methods (the b-carotene bleaching method, DPPH radical scavening method and Rancimat assay), while thyme and wild thyme showed weaker and relatively similar antioxidant activity.

Optimization of amylase and protease production from Aspergillus awamori in single bioreactor through EVOP factorial design technique

Abstract: Summary Evolutionary operation (EVOP) factorial design technique was explored in order to economically produce amylase and protease at their optimum level in a single bioreactor by modified solid-state fermentation. Maximum yields of amylase and protease were achieved, using wheat bran as a substrate by a highly potent, locally isolated strain of Aspergillus awamori: Nakazawa MTCC 6652. The strain had been induced previously, inferring the ability to produce both enzymes concomitantly in a single bioreactor with their maximum capacity. The highest secretion of amylase and protease were measured to be 9420.6 and 1930 U/g, respectively, at 37 °C. pH and relative humidity were found to be optimum at 4 and 85 %, evaluated through EVOP method.

Production, Purification, Stability and Efficacy of Bacteriocin from Isolates of Natural Lactic Acid Fermentation of Vegetables

Abstract: Summary The antimicrobial activity of partially purified bacteriocin produced during naturallactic acid fermentation of carrot, radish and cucumber was assessed and characterized.Out of ten strains, the isolated strain CA 44 of Lactobacillus genus from carrot fermentationproduced bacteriocin with maximum antimicrobial activity against Escherichia coli , Staphy-lococcus aureus and Bacillus cereus, though it was more effective against E. coli than others . Bacteriocin was stable at up to 100 °C but its activity declined compared to that at 68 °Cand was completely lost at 121 °C. The maximum antimicrobial activity was retained with-in the pH range of 4–5, but it was adversely affected by the addition of papain. Bacteriocinwas also effective against B. cereus in different fruit products (pulp, juice and wine) indi-cating its potential application as a biopreservative in fruit products. Key words : antimicrobial, bacteriocin, lactic acid fermentation, Lactobacillus , Staphylococcus,Bacillus cereus

Biotechnological Production of Vitamins

Abstract: Summary Vitamins are defined as essential micronutrients that are required in trace quantity and cannot be synthesized by mammals. Apart from their in vivo nutritional and physiological roles as growth factors for men, animals, plants and microorganisms, vitamins are now being increasingly introduced as food/feed additives, as medical-therapeutic agents, as health aids, and also as technical aids. Production of vitamins by chemical synthesis, or extraction from their known sources has serious disadvantages. This led to an increased interest in substituting these processes with biotechnological processes. For several of these compounds microbiological and algal processes exist, or are rapidly emerging. Different methods like media optimization, mutation and screening, genetic engineering and biocatalyst conversion have been used for improvement of the production of vitamins. The survey describes the current state of vitamin production by biotechnological processes and their significance, as compared to the existing chemical processes.

Effects of various process parameters on the production of gamma-linolenic acid in submerged fermentation

Abstract: Summary Studies were carried out on the fermentative production of g-linolenic acid (GLA) using seven strains belonging to Mucorales. An oleaginous fungal strain, isolated from the Western Ghats of Kerala produced GLA at a level of 8 % (by mass), when grown in a complex medium containing glucose as the sole carbon source. Effects of different culture conditions were investigated in shake flasks. Maximum dry biomass and total GLA obtained were 48.4 g/L and 636 mg/L, respectively, in the culture cultivated at 30 °C and 200 rpm for 7 days. Among the organic nitrogen sources investigated, yeast extract, and combination of corn steep liquor and baker’s yeast in 1:1 ratio were useful for enhancing the GLA production and the effects were comparable.

Optimization of the Medium for the Production of Cellulase by the Mutant Trichoderma reesei WX-112 Using Response Surface Methodology

Abstract: Summary The mutant strain Trichoderma reesei WX-112 with high cellulase activity was isolated by a newly invented plate. The mutant’s ability to produce cellulase increased 1.95 times after the treatment with UV and N-methyl-N’-nitro-N-nitrosoguanidine (MNNG). Also, the medium composition was optimized using response surface methodology (RSM). A fractional factorial design (2 6–2 ) was applied to elucidate the medium components that significantly affect cellulase production. The concentration of Avicel and soybean cake flour in the medium were significant factors. The steepest ascent method was used to locate the optimal domain and a central composite design was used to estimate the quadratic response surface from which the factor levels for maximum production of cellulase were determined. The composition of fermentation medium optimized with response surface methodology was (in g/L): wheat bran 30, Avicel 36.4, soybean cake flour 24.7, KH2PO44 and corn steep flour 5. Compared to the original medium, the cellulase activity increased from 7.2 to 10.6 IU/mL.

Advances in Mushroom Research in the Last Decade

Abstract: Summary There has been a lot of progress in mushroom science and biotechnology in the last decade The optimization of PFGE separation of fungal chromosomes allowed the study of the molecular karyotype of mushrooms and the assignment of genes to chromosomes There are 115 genes encoded from different species of mushrooms Cross breeding continues to be the principal method, but it is accompanied by the analyses of RAPD or RFLPs methods The genetic makers are used and introduced into commercial large hybrids via introgression breeding The complex traits such as yield, resistance to disease and quality characteristics, and quantitative traits more than one quantitative trait locus (QTL) are found and used in practice The transformants or transgenic mutant strains were obtained by Agrobacterium system or particle bombardment At least 651 species representing 182 genera of hetero- and homobasidiomycetes mushrooms were researched containing antitumor or immunostimulating polysaccharides Ergosterol in the lipid fraction was identified as one of the most active constituents New sesquiterpenoid hydroquinones, steroids, oxalic acid, triterpenes, water-soluble lignins, sulfated polysaccharides, protein-bound polysaccharides are researched intensively as antimicrobial or antiviral agents Many small molecular mass compounds exhibit cytotoxic activities, such as illudins, leaianafulvene, triterpenes (ganoderic acids), acetoxyscirpenediol, ergosterol peroxide, sterols There are many other compounds or activities found in the mushrooms, such as antioxidative, hypoglycemic action, anti-inflammatory effect, hepatoprotective compounds, psychoactive compounds and activities

Why Solid-State Fermentation Seems to be Resistant to Catabolite Repression?

Abstract: Summary A critical review of the phenomenon of resistance to catabolite repression of enzyme synthesis by solid-state fermentation (SSF) has been made The practical and theoretical importance of such phenomenon is commented, together with the current ideas to explain it Namely, the possible existence of microscopic gradients within the mass of cell aggregates, or the changes in cell permeability to sugars, which would explain the fact that no catabolite repression is observed in SSF when sugar concentration is as high as 100 g/L, despite the fact that in conventional submerged fermentation (SmF) strong inhibition of inducible enzymes is observed whenever sugar concentration is higher than 10 g/L Two alternative mathematical models are presented in order to explore the feasibility of those hypotheses, but also to help the planning of future experiments in order to understand the microscopic physiology of SSF A priori, both hypotheses will explain the phenomenon, but only if the local diffusivity or permeability of sugars in SSF have changed in various orders of magnitude as compared to the observed magnitudes in SmF systems

Kataliticka svojstva ekstrakta lipaze iz plijesni Aspergillus niger

Abstract: Summary Screening of lipolytic strains using Rhodamine-B/olive oil plate technique allowed the selection of Aspergillus niger MYA 135. Lipase production in submerged culture containing 2 % olive oil was enhanced by more than 50 % compared to basal cultural conditions. Optimal catalytic conditions for olive oil-induced lipase were pH=6.5 and 30–35 °C. These values were shifted to the acid region (4.0–6.5) and 35–37 °C when lipase extract was produced under basal conditions. Slight changes of the residual lipase activity against the pH were found. However, preincubation at either 37 or 40 °C caused an increase in the olive oil-inducible lipolytic activity. On the contrary, lipase residual activity decreases in the 30–55 °C range when it was produced in basal medium. Lipolytic extracts were almost not deactivated in presence of 50 % water-miscible organic solvents. However, water-immiscible aliphatic solvents reduced the lipase activity between 20 and 80 %.

Istraživanje proizvodnje pektinaze iz regionalnog poljoprivrednog otpada s pomoću plijesni Aspergillus niger

Abstract: Summary The aim of this study was to evaluate locally available pectin rich agrowastes, viz. lemon peel, sorghum stem and sunflower head, as substrates for the production of pectinase by Aspergillus niger DMF 27 and A. niger DMF 45 in submerged fermentation (SmF) and solid-state fermentation (SSF) systems, respectively. The maximum amount of endo(4.8 U/g) and exopectinases (17.2 U/g) was obtained from sunflower head followed by lemon peel (endopectinase 2.0 and exopectinase 10.2 U/g) in solid-state system. The increased level in the production of pectinases was noticed when the agrowastes were supplemented with additional carbon and nitrogen sources, and supplementation of sucrose was more effective than glucose in SSF. But, glucose yielded more pectinases in SmF. Among the nitrogen sources, ammonium sulphate raised the production level of pectinases from all the substrates in both SmF and SSF systems.

Fungal Invertase Expression in Solid-State Fermentation

Abstract: Summary In this study invertase activity expression in Aspergillus niger Aa-20 was evaluated under different concentrations of two substrates using solid-state fermentation (SSF) on polyurethane foam. Glucose was used as repressor and sucrose was the inducer. Invertase production increased when glucose was present in the medium (up to 100 g/L); however, higher concentration than this reduced the enzyme production. Induction-repression ratio obtained using any glucose concentration was at least 2.5 times higher than that under basal conditions (without inducer).

Effect of Casein Hydrolysates on Yogurt Fermentation and Texture Properties during Storage

Abstract: Summary Effects of casein hydrolysates by papain on acidification of the yogurts and growth of probiotic bacteria during yogurt fermentation have been investigated. The viability of probiotic bacteria and texture characteristics of the yogurts during storage at 4 °C have been evaluated. The hydrolysates strongly decreased the fermentation and coagulation time of the yogurts. The post-fermentation acidification was retarded by the hydrolysates. The hydrolysates increased the probiotic counts during initial fermentation stage. The growth of the probiotic organisms decreased at the final stage. Survival of probiotic bacteria was improved by the hydrolysates. The hydrolysates significantly (p<0.05) increased the adhesiveness of the yogurts except for 0.5 % of hydrolysate with degree of hydrolysis of 8.5 %. The sensory evaluation scores of the yogurts were significantly (p<0.05) improved by the hydrolysates after the storage. The effect of casein hydrolysates on fermentation and texture properties was related to the molecular mass of the hydrolysates.