Showing papers in "Food Technology and Biotechnology in 2010"

The potential of probiotics: a review.

Abstract: Carlos Ricardo Soccol1*, Luciana Porto de Souza Vandenberghe1, Michele Rigon Spier1, Adriane Bianchi Pedroni Medeiros1, Caroline Tiemi Yamaguishi1, Juliano De Dea Lindner1,2, Ashok Pandey3 and Vanete Thomaz-Soccol1,4 Bioprocess Engineering and Biotechnology Department, Federal University of Paraná (UFPR), 81531-990 Curitiba-PR, Brazil State University of Santa Catarina, Food Engineering Department, BR 282, Km 573 Santa Teresinha, 89870-000 Pinhalzinho SC, Brazil Biotechnology Division, National Institut for Interdisciplinary Science and Technology, CSIR, Trivandrum, 695 019, India Positivo University, Industrial Biotechnology Department, Av. Pedro Parigot de Souza 5300, 81280-330, Curitiba-PR, Brazil

Antimicrobial Activity – The Most Important Property of Probiotic and Starter Lactic Acid Bacteria

Abstract: Summary The antimicrobial activity of industrially important lactic acid bacteria as starter cultures and probiotic bacteria is the main subject of this review. This activity has been attributed to the production of metabolites such as organic acids (lactic and acetic acid), hydrogen peroxide, ethanol, diacetyl, acetaldehyde, acetoine, carbon dioxide, reuterin, reutericyclin and bacteriocins. The potential of using bacteriocins of lactic acid bacteria, primarily used as biopreservatives, represents a perspective, alternative antimicrobial strategy for continuously increasing problem with antibiotic resistance. Another strategy in resolving this problem is an application of probiotics for different gastrointestinal and urogenital infection therapies.

Surfactin – A Review on Biosynthesis, Fermentation, Purification and Applications

Abstract: Surfactin, a bacterial cyclic lipopeptide, is produced by various strains of Bacillus subtilis and is primarily recognized as one of the most effective biosurfactants. It has the ability to reduce surface tension of water from 72 to 27 mN/m at a concentration as low as 0.005 %. The structure of surfactin consists of seven amino acids bonded to the carboxyl and hydroxyl groups of a 14-carbon fatty acid. Surfactin possesses a number of biological activities such as the ability to lyse erythrocytes, inhibit clot formation, lyse bacterial spheroplasts and protoplasts, and inhibit cyclic 3,5-monophosphate diesterase. The high cost of production and low yields have limited its use in various commercial applications. Both submerged and solid-state fermentation have been investigated with the mutational approach to improve the productivity. In this review, current state of knowledge on biosynthesis of surfactin, its fermentative production, purification, analytical methods and biomedical applications is presented.

Production of Fructooligosaccharides from Inulin by Endoinulinases and Their Prebiotic Potential

Abstract: Summary The production and applications of food-grade oligosaccharides are increasing rapidly. Amongst them, fructooligosaccharides represent one of their major classes in terms of production. They are relatively new functional food ingredients that have great potential as prebiotics, apart from having a number of desirable characteristics which are beneficial to the health of consumers. These are manufactured either by transfructosylation of sucrose using b-fructofuranosidases or hydrolysis of inulin by endoinulinases. Inulin, a polyfructan, occurs as a reserve carbohydrate in many plant families, representing more than 30 000 species. It is a potent substrate both for the production of inulinases and fructooligosaccharides. The review focuses on the recent developments in the production of fructooligosaccharides from inulin by endoinulinases, their prebiotic potential, functionalities and applications in food industry, and future perspectives.

Modern Biotechnological Polymer Synthesis: A Review

Abstract: Summary The industrial implementation of cost- and eco-efficient production of bio-based polymeric materials such as polyhydroxyalkanoates (PHAs) or polylactic acid (PLA) requires the comprehension of all process steps The article at hand provides an insight into recent advances in allocation, pretreatment and utilization of raw materials available for biopolymer production in different areas of the world Further, the high potential and risks of applying continuous process conduction in comparison with batch and fed batch fermentation mode are elucidated It is shown that the process design for continuous PHA production strongly depends on the kinetic characteristics for growth and product formation of the applied production strain In addition, the triggering of the biopolymer properties by fine-tuning of the polyester composition during biosynthesis is demonstrated Here, the impact of certain process parameters like the partial oxygen tension on the intracellular metabolic fluxes and the supplementation of cosubstrates on the polyester composition are discussed In addition, such specialists among microbes are presented that possess the metabolic prerequisites to accumulate high-quality copolyesters merely from cheap unrelated carbon sources without the necessity for supplying expensive cosubstrates In the field of downstream processing, sustainable methods for product isolation during biopolymer production that do not have a negative influence on the environment are presented

Polysaccharides from probiotics: New developments as food additives

Abstract: Summary Microbial polysaccharides with nutraceutical potential and bioactive properties have been investigated in detail during the last few decades. There is an increasing demand in food industries for live microbes or polysaccharides produced by them which assert health benefits other than dietetic constituents. Although there are a large number of exopolysaccharide (EPS)-producing bacteria, the titers are low for commercialization. This manuscript deals with the polysaccharides produced by probiotic strains, with major emphasis on the EPSs, their properties, applications and some of the strategies adopted which would be helpful in better understanding of the process in the near future. Research on the improved EPS biosynthesis is essential for obtaining high yields. Therefore, to reach commercialization, metabolic engineering must be applied.

Lipids from Lipomyces starkeyi.

Abstract: Summary The oleaginous yeast Lipomyces starkeyi is interesting for industrial-scale production of biodiesel. Here it is reported that this yeast is able to digest unsaccharified, soluble potato starch. In these experiments, the cultivation time of Lipomyces starkeyi was reduced to half of the previously reported values. The effect of C:N molar ratio was studied on growth and lipid content of L. starkeyi in media containing glucose or potato starch as C-source. At a C:N molar ratio of 61.2 in glucose medium, the lipid content was measured at 30 % of the dry matter. It was established that the cellular lipid content increased with increasing C:N molar ratio, but the cell yield decreased. In a pH-controlled 1-litre agitated and aerated bioreactor, batch cultivation on glucose resulted in 23 % lipids in cells on dry mass basis (dm), cell yield of 0.25 g/g glucose, and lipid yield of 0.06 g/g glucose. Under the same operating conditions, fed-batch cultivation with discrete glucose additions resulted in 27 % lipids, cell yield of 0.28 g/g glucose, and lipid yield of 0.08 g/g glucose. On soluble but unsaccharified sweet potato starch, cell yield was 0.41 g/g glucose equivalent, lipid yield 0.16 g/g glucose equivalent, and lipid content in cells 40 %. The major fatty acids in the cells were C16:0 and C18:1 (accounting for 85–90 % by mass of the total lipids) with the rest being C16:1 and C18:0. All of these are valuable lipids for biodiesel production. Based on these results, wastes and wastewater from food industry and sewage sludge could serve as sources for the production of biodiesel.

The use of response surface methodology in optimization of lactic acid production: focus on medium supplementation, temperature and pH control.

Abstract: Summary Two response surface methodologies involving central composite designs have been successfully applied to evaluate the effect of cheese whey, corn steep liquor, ammonium sulphate, temperature and pH control on lactic acid fermentation by Lactobacillus sp. LMI8 isolated from cassava flour wastewater. In the first central composite design, corn steep liquor and ammonium sulphate were investigated as low-cost nitrogen sources in combination with other components to substitute yeast extract for economical production. The best results were obtained with 55 g/L of lactose, 15 g/L of corn steep liquor and 5.625 g/L of ammonium sulphate. At the maximum point, the lactic acid concentration reached 18.68 g/L. After defining the optimal nutritional conditions for lactic acid production, a second central composite design was performed to determine the extent to which temperature and pH influence the lactic acid production with the aim of improving the fermentation process. The second-order polynomial regression model determined that the maximum lactic acid production of 52.37 g/L would be obtained when the optimum temperature and pH were 39.6 °C and 5.9, respectively. Comparing the lactic acid production in shake flask fermentation, there was an increase of 180 % after 30 h of processing, with a conversion efficiency of about 86.12 % of the initial lactose. In addition, lactic acid produced from whey lactose by Lactobacillus sp. LMI8 was optically almost pure D-lactic acid (over 98 % of total lactic acid produced).

Evaluation of phenolic content and antioxidant capacity of blueberry cultivars (Vaccinium corymbosum L.) grown in the Northwest Croatia

Abstract: The aim of this study is to evaluate the content of phenolics: total phenols (TPC), flavonoids (TF), anthocyanins (TA), flavan-3-ols (TF3ols), as well as total antioxidant capacity (TAC) and reducing power (RP) in four blueberry cultivars (Vaccinium corymbosum L.) introduced in the Northwest Croatian climate conditions. Phenolic compounds were measured by spectrophotometric methods, TAC was determined using DPPH and ABTS assays and RP by FRAP assay. All cultivars contained high mass fraction of TPC, TF, TA and lower mass fraction of TF3ols. Among the researched fruits, Sierra cultivar contained the highest amounts of all groups of phenolics, followed by Elliott>Bluecrop³Duke. Significant differences were observed in phenolic mass fraction among different cultivars and growing seasons (p<0.05), and phenolic compounds were significantly higher in growing season 2006. Examined cultivars possess high antioxidant capacity and reducing power, and all phenolics were highly correlated with TAC and RP (R=0.46 to 0.99). The study indicated that growing and climate conditions in Northwest Croatia are convenient for introducing blueberry cultivars. Generally, blueberry fruits are a rich source of phenolics, which show evident antioxidant capacity.

Antioxidant activity of whey from milk fermented with Lactobacillus species isolated from Nigerian fermented foods.

Abstract: Summary Eight Lactobacillus isolates obtained from five indigenous fermented foods (ogi, ogi baba, wara, kunnu and ugba) were investigated. Wara is a dairy-based food while the others are not dairy-based. The bacteria were isolated on MRS agar and purified by successive streaking on the same medium. The whey fraction of skimmed milk fermented with each isolate was assayed for radical scavenging effects using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. All the whey fractions showed radical scavenging activities. The five isolates with the highest activities were selected. On the basis of Gram stain reaction, cellular morphology, biochemical tests and carbohydrate utilization profiles they were identified as strains of Lactobacillus brevis, L. fermentum, L. plantarum, L. casei and L. delbrueckii. The antioxidant activities of whey fractions from 24-hour fermentations with the selected organisms were investigated using both radical scavenging effects and lipid peroxidation inhibitory activity. The radical scavenging activity was generally higher than the lipid peroxidation inhibition, except in the L. plantarum strain, which did not show any significant difference in both activities. The probiotic potential of the isolates was evaluated by pH and bile tolerance. None of the selected isolates showed any growth at pH=2.0 but L. casei and L. delbrueckii survived at this pH. Four of the five selected isolates were able to grow in 0.5 % dehydrated bile, with L. casei strain showing the highest level of growth, followed by L. delbrueckii. L. plantarum strain was not bile tolerant. The ability of L. casei and L. delbrueckii strains to survive at pH=2 and grow in the presence of bile indicates that the isolates may be able to colonize the gastrointestinal tract. The findings of this study indicate that Lactobacillus strains isolated from indigenous Nigerian fermented foods could be useful as starter cultures to provide antioxidants in food and that fermented milk may serve as a delivery vehicle for antioxidative, probiotic lactobacilli from non-dairy sources.

Phytochemical content of some black (Morus nigra L.) and purple (Morus rubra L.) mulberry genotypes.

Abstract: Summary Bright black (Morus nigra) and purple mulberry (Morus rubra) are particularly desirable fruits in Turkey. More recently, the interest in these bright black and purple mulberry fruits has also increased because of the popularization of healthy properties of these fruits. The study was carried out in 2008 aiming to determine the antioxidant activity (ferric reducing ability of plasma, FRAP), total phenolic, total anthocyanin, mineral, soluble solid, vitamin C, and total acid content of four black and four purple mulberry genotypes grown in Turkey. The results show that black mulberry genotypes have a higher bioactive content than purple mulberry genotypes. The average total phenolic content and total anthocyanins of black mulberry genotypes were 2149 mg of gallic acid equivalent (GAE) per g and 719 mg of cyanidin 3-glucoside equivalent (Cy 3-glu) per g of fresh mass. In purple mulberry, these values were for GAE 1690 mg/g and for Cy 3-glu 109 mg/g on fresh mass basis. The average antioxidant activity of black mulberry genotypes was also found to be higher than that of the purple ones according to FRAP assay (Trolox equivalent (TE) per fresh mass of black and purple mulberries was 13.35 and 6.87 mmol/g, respectively).

Physicochemical, Textural and Sensory Characteristics of Probiotic Soy Yogurt Prepared from Germinated Soybean

Abstract: Soymilk prepared from germinated soybean [Glycine max (L.) Merrill] with different hypocotyl lengths was fermented at 42 °C for approx. 4 h to produce soy yogurt (sogurt) with the combined probiotics of Lactobacillus helveticus B02, Streptococcus thermophilus IFFI 6038 and Lactobacillus bulgaricus AS1.1482. The physicochemical, textural and sensory characteristics of the fermented products were subsequently analyzed. Results showed that sogurt prepared from germinated soybean with the length of hypocotyls of 3 cm displayed lower pH and higher titratable acidity, and appeared to be more acceptable by the trained panel than sogurts prepared from soybean with hypocotyl length of 0 and 6 cm (p<0.05). Texture profile analysis demonstrated that the hardness of sogurts significantly decreased (from 26.71 to 16.89 g), while the adhesiveness significantly increased (from –71.77 to –31.94 g·s) as hypocotyl length increased (p<0.05). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) profile of soymilk demonstrated that the a’ and a subunits of b-conglycinin (7S) and the acidic chains of glycinin (11S) were gradually degraded, which may be partly responsible for the decline of water holding capacity and the amelioration of textural properties of the germinated soy yogurt. The total concentration of free amino acids obtained by high-performance liquid chromatography (HPLC) was 515.78 mg/mL in the soymilk from ungerminated soybean (S0), while it reached 847.44 and 880.75 mg/mL from soybean with 3-cm (S3) and 6-cm (S6) hypocotyls, respectively. Some of the increased levels of free amino acids may account for the improvement of flavour and reproduction of lactic acid bacteria. It could be concluded that, with appropriate germination, the physicochemical and textural properties as well as sensory characteristics of sogurt could be improved significantly.

Biocontrol of Grey Mould Disease on Grape Caused by Botrytis cinerea with Autochthonous Wine Yeasts

Abstract: Summary Biocontrol activities of different yeast species and strains isolated from grape/must/ wine environments have been compared to those of commercially available antagonistic yeast species of Candida oleophila. A total of 591 yeast isolates were tested in a preliminary screening on agar to select isolates showing inhibitory effect against Botrytis cinerea, the plant pathogen causing grey mould disease on grape. Yeast species Aureobasidium pullulans, Metschnikowia pulcherrima and Pichia guilliermondii showed, on average, higher biocontrol activity than commercially used yeast Candida oleophila. Furthermore, these three species and Saccharomyces cerevisiae, which is potentially interesting biocontrol agent against grey mould of grapes, were selected for their inhibitory effects and assayed in vitro on different solid synthetic media for their antagonistic capacity towards B. cinerea. The results indicate that the composition of the medium had an impact on the biocontrol activity of yeast species and strains, as Saccharomyces cerevisiae showed the highest antagonistic activity against B. cinerea when tested on media with increased concentrations of glucose. The antagonistic activity of selected yeast strains was finally determined on wounded and sound grape berries of cultivars Rebula and Chardonnay for their ability to inhibit infection by B. cinerea moulds. Results suggest that antagonist yeasts with the potential to control B. cinerea on grape can be found among the microflora associated with the berries.

Application of Proteomics in Food Technology and Food Biotechnology: Process Development, Quality Control and Product Safety

Abstract: Summary Human food is a very complex biological mixture and food processing and safety are very important and essential disciplines. Proteomics technology using different high-performance separation techniques such as two-dimensional gel electrophoresis, one-dimensional and multidimensional chromatography, combined with high-resolution mass spectrometry has the power to monitor the protein composition of foods and their changes during the production process. The use of proteomics in food technology is presented, especially for characterization and standardization of raw materials, process development, detection of batch-to-batch variations and quality control of the final product. Further attention is paid to the aspects of food safety, especially regarding biological and microbial safety and the use of genetically modified foods.

A new probiotic cheddar cheese with high ACE-inhibitory activity and γ-aminobutyric acid content produced with koumiss-derived Lactobacillus casei Zhang.

Abstract: Summary Cheddar cheese has been manufactured with Lactobacillus casei Zhang as the dairy starter adjunct. L. casei Zhang had previously been isolated from koumiss collected from Xilin Guole in Inner Mongolia and characterized in detail with regard to their probiotic potential. The addition of L. casei Zhang to Cheddar cheese had no adverse effects on sensory criteria. The cheese made with 0.1, 1 an d2%o f the probiotic strain L. casei Zhang adjuncts contained high levels of the Lactobacillus after 6 months of ripening with final counts of 9.6·10 7 , 7.7·10 7 and 1.02·10 8 CFU/g, respectively. In the ripe control cheese, without the addition of probiotic strain L. casei Zhang, the number of Lactobacillus reached 5.7·10 7 CFU/g. Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) analysis was used to distinguish the added L. casei Zhang from the natural flora of the cheese and to determine whether L. casei Zhang grew in the cheese. ACE-inhibitory activity and g-aminobutyric acid (GABA) concentrations in the cheese were measured. Compared with control cheese, experimental cheese with 0.1, 1 an d2%o f probiotic strain L. casei Zhang revealed some increase in ACE-inhibitory activity and GABA mass fraction. In the present study, the production of both ACE-inhibitory activity and GABA in the probiotic cheese with the L. casei Zhang adjunct isolated from koumiss has been found for the first time. The results suggest that cheese with the probiotic strain L. casei Zhang showed good potential for application in the management of hypertension.

Investigation of Gelatin Polypeptides of Jellyfish (Rhopilema esculentum) for Their Antioxidant Activity in vitro

Abstract: Summary Jellyfish gelatin was hydrolyzed by different proteases to obtain antioxidative polypeptides. The gelatin hydrolysate obtained by progressive hydrolysis using trypsin and Properase E exhibited the highest hydrolysis degree and antioxidant activity. Three series of gelatin polypeptides (SCP1, SCP2 and SCP3) were obtained by ultrafiltrating the gelatin hydrolysate through molecular mass cut-off membranes of 10, 6 and 2 kDa, respectively. Amino acid composition analysis showed that SCP3 had the highest total hydrophobic amino acid content. The in vitro antioxidant tests demonstrated that SCP2 had the strongest hydroxyl radical and hydrogen peroxide scavenging activities and metal chelating ability, while SCP3 showed the highest reducing power, antioxidant activity in linoleic acid emulsion system and superoxide anion radical scavenging activity. The results support the feasibility of jellyfish gelatin as a natural antioxidant polypeptide provider, and enzymatic hydrolysis and ultrafiltration could be potent future processing technologies to utilize the abundant jellyfish resource.

Polyphenols and volatiles in fruits of two sour cherry cultivars, some berry fruits and their jams.

Abstract: This paper reports about the content of polyphenols and volatiles in fresh fruits of two sour cherry cultivars (Marasca and Oblacinska), some berry fruits (strawberry Maya, raspberry Willamette and wild blueberry) and the corresponding low sugar jams. Phenolic compounds (hydroxybenzoic and hydroxycinnamic acids, flavan-3-ols and flavonols) were determined by high-performance liquid chromatography (HPLC). Those found in the fruits were also found in the jams. Jams contained lower amounts of polyphenols than fresh fruits, but their overall retention in jams was relatively high. Among fruits, sour cherry Marasca had the highest level of polyphenols, while sour cherry Marasca jam and raspberry Willamette jam had the highest level of polyphenols among jams. The major flavonoid in all investigated fruits, except in sour cherry Oblacinska, was (–)-epicatechin. Sour cherry Marasca had the highest level of (–)-epicatechin (95.75 mg/kg), and it also contained very high amounts of flavonols, derivatives of quercetin and kaempferol. Hydroxybenzoic acids (HBAs) were not found in sour cherries Marasca and Oblacinska but were found in berry fruits and jams. Phenolic compound (+)-gallocatechin was found only in Marasca fruit and jam. Ellagic acid was found in the highest concentration in raspberry Willamette fruit and jam. Hydroxycinnamic acids (HCAs) were found in all the investigated fruits, with the exception of a derivative of ferulic acid, which was not found in strawberry. Derivatives of caffeic, p-coumaric and chlorogenic acids were found in all the investigated fruits, with chlorogenic acid being the most abundant, especially in sour cherry Marasca. Volatiles were determined by gas chromatography (GC) and expressed as the peak area of the identified compounds. All investigated volatiles of fresh fruit were also determined in the related jams with relatively high retention. Sour cherries Marasca and Oblacinska contained the same volatile compounds, but Marasca had higher level of total volatiles. The main volatile compound in both sour cherry cultivars was benzaldehyde (characteristic cherry aroma compound), which was followed by hexanal, 2-hexenal, 2-heptanone, linalool, nerol, and a-terpineol. Our results show that g-decalactone and linalool were the most abundant volatile compounds in strawberry Maya and raspberry Willamette, respectively. The most abundant group of volatiles in wild blueberry was esters, and they were followed by terpenes, ethyl butanoate and linalool.

Evaluation of Streptomyces as a Probiotic Feed for the Growth of Ornamental Fish Xiphophorus helleri

Abstract: Summary The potential of Streptomyces as a probiotic feed for the growth of ornamental fish Xiphophorus helleri has been investigated. The Streptomyces strains used as probiotics were isolated from the marine sponges, namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis. Seven probiotic feeds were prepared and their effects were compared with those of control diet containing no probiotics. After 50 days of feeding trials, the growth parameters, namely absolute growth rate, specific growth rate, relative growth rate and feed conversion efficiency were found to be significantly (p<0.05) higher in groups that received probiotic feed additive than in the control, whereas feed conversion ratio was lower. The fish fed with probiotic feed showed significant improvement in length than the fish fed with control feed. Thus it was found that in addition to being effective antibiotic agents against harmful pathogens, Streptomyces could also promote the growth of fish effectively. Marine Actinobacteria, particularly Streptomyces, could thus be a promising probiotic in aquaculture.

The stability and antioxidant activity of anthocyanins from blueberry.

Abstract: Anthocyanins from highbush blueberry (Vaccinium corymbosum L.) have tremendous potential as natural colorants and functional food with pharmaceutical purposes in food applications. To exploit the potential for food applications, the stability and antioxidant activity of anthocyanins present in blueberries have been studied. The results indicate that anthocyanins from blueberry were stable against the low pH (£5.0), NaCl (0.125–0.500 mol/L), sucrose (0.584–2.336 mol/L) and preservative (sodium benzoate, 0.035–0.140 mol/L), but were sensitive to alkaline conditions (37.0), high temperature (380 °C), light (natural light), oxidizing agent (H2O2, 0.5–2.0 %) and reducing agent (Na2SO3, 0.005–0.040 mol/L). At concentrations of 25 and 50 mg/mL, anthocyanins from blueberry could protect ECV-304 cells against oxidative damage induced by H2O2. These results suggest that anthocyanins from blueberry can be regarded as a potential colorant for some acidic (pH£5.0) food products and could be used as health food to prevent diseases arising from oxidative processes.

Characterization of β-glucans isolated from brewer's yeast and dried by different methods.

Abstract: Summary Two different procedures have been used for isolation of water-insoluble b-glucans from brewer’s yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained b-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. b-Glucan preparations obtained by AA and AAM isolations had similar values of dry mass, total polysaccharides, proteins and organic elemental microanalysis. The mass fractions of b-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1®3)-b-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in b-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.

Effect of Maturity and Geographical Region on Anthocyanin Content of Sour Cherries (Prunus cerasus var. marasca)

Abstract: The influence of different stages of maturity on the anthocyanin content and colour parameters in three sour cherry Marasca ecotypes grown in two Dalmatian geographical regions has been studied. Anthocyanins were determined by HPLC-UV/VIS PDA analysis and the colour of fruit flesh and skin was measured by tristimulus colourimeter (CIELAB system). The major anthocyanins in all ecotypes at all stages of maturity were cyanidin 3-glucosylrutinoside and cyanidin 3-rutinoside, whereas pelargonidin glycosides were determined in lower concentrations. During ripening, anthocyanins did not change uniformly, but in most ecotypes, they were determined in higher concentrations at the last stage of maturity (3.18 to 19.75 g per kg of dry matter). The formation of dark red, almost black colour in ripe Marasca cherries decreased redness (a*), brightness (L*) and colour intensity (C*). The results of two-way ANOVA test indicated that the growing region significantly influenced the accumulation of individual anthocyanins and L* value during ripening, while ecotype and the interaction between the growing region and the ecotype significantly affected total anthocyanin content of sour cherry.

Production of Carotenoid-/Ergosterol-Supplemented Biomass by Red Yeast Rhodotorula glutinis Grown Under External Stress

Abstract: Summary The aim of this study is to compare the production of biomass enriched with carotenoids and ergosterol by yeast strain Rhodotorula glutinis CCY 20-2-26 grown under optimal growth conditions and in the presence of exogenous stress factors. R. glutinis cells were exposed to UV irradiation, oxidative stress (2–10 mmol/L H2O2) and osmotic stress (2–10 % NaCl). During the experiment, growth characteristics and the production of biomass, carotenoids and ergosterol were evaluated. Experiments were carried out in Erlenmeyer flasks and in laboratory fermentor. First, R. glutinis cells were exposed to higher concentration of stress factors added into the production medium. Further, low concentrations of NaCl and H2O2 were added to the inoculum medium or to both inoculum and production media. Exposure of red yeast cells to all tested stress factors resulted in higher production of carotenoids as well as ergosterol, while biomass production was changed only slightly. Under high stress, 2–3 times increase of b-carotene was observed. The addition of low salt or peroxide concentration into the inoculation media led to about 2-fold increase of carotenoid production. In Erlenmeyer flasks the best effect on the carotenoid and ergosterol production (3- to 4-fold increase) was exhibited by the combined stress: the addition of low amount of NaCl (2 %) into the inoculum medium, followed by the addition of H2O2 (5 mmol/L) into the production medium. The production of ergosterol in most cases increased simultaneously with the production of carotenoids. Cultivation of R. glutinis carried out in a 2-litre laboratory fermentor was as follows: under optimal conditions about 37 g/L of yeast biomass were obtained containing approx. 26.30 mg/L of total carotenoids and 7.8 mg/L of ergosterol. After preincubation with a mild stress factor, the yield of biomass as well as the production of carotenoids and ergosterol substantially increased. The best production of enriched biomass was obtained in the presence of peroxide in the inoculation medium (52.7 g/L of biomass enriched with 34 mg/L of carotenoids) and also under combined salt/peroxide or salt/salt stress (about 30–50 g/L of biomass enriched with 15–54 mg/L of total carotenoids and about 13–70 mg/L of ergosterol). R. glutinis CCY 20-2-26 could be used as a potential biotechnological producer of carotenoid-rich biomass.

Comparative study of response surface methodology, artificial neural network and genetic algorithms for optimization of soybean hydration.

Abstract: Summary The present investigation deals with the modelling and optimization of soybean hydration for facilitating soybean processing and it focuses on maximization of mass gain, water uptake and protein retention in the bean. Process variables considered for optimization were: soybean to water ratio (1:2.48 obtained with response surface methodology, RSM, and 1:1.19 obtained with artificial neural network and genetic algorithm, ANN/GA), time (2.0 h using RSM and 8.0 h using ANN/GA) and temperature (40.0 °C using RSM and 45.1 °C using ANN/GA). The findings in this first report on optimization of soaking conditions for soybean hydration employing response surface methodology, hybrid artificial neural network and genetic algorithms reveal a substantially better alternative to the time-consuming soaking process, extensively practiced in industries, in terms of process time economy. Reasonably accurate neural network model (regression coefficient of 0.9443) was obtained based on the experimental data. The optimized set of process conditions was predicted through genetic algorithm, and the effectiveness of the ANN/GA model, validated through experiments, was indicated by significant correlations (R 2 and mean squared error (MSE) being 0.9380 and 5.9299, respectively). RSM also resulted in accurate models for predicting percentage mass gain, percentage water uptake and percentage protein retention (R 2 and MSE in the range of 0.889–0.9297 and 0.80–4.94, respectively).

Enzyme Production and Nitrogen Fixation by Free, Immobilized and Coimmobilized Inoculants of Trichoderma harzianum and Azospirillum brasilense and Their Possible Role in Growth Promotion of Tomato

Abstract: A plant growth-promoting rhizobacterium (Azospirillum brasilense strain Az) and a biocontrol fungus (Trichoderma harzianum strain T24) have been evaluated for their individual and combined production of hydrolytic enzymes, nitrogen fixation and their possible role in growth promotion of tomato seedlings. The studied organisms were inoculated as free or calcium alginate-encapsulated cells. All freshly prepared macrobeads showed high encapsulation capacity (EC/%) of inocula compared with dry macrobeads. Results of enzyme production did not exhibit consistent pattern of the effect of encapsulation process on enzyme production. Beads entrapping bacterial and/or fungal cells were used successfully in 3 repeated cycles in the presence of fresh sterile culture medium in each growth cycle. Enzyme production by immobilized bacterial and/or fungal cells increased as the growth cycles were repeated. Co-culturing of A. brasilense with T. harzianum (free or immobilized) in semisolid nitrogen deficient medium (N-free medium) enabled A. brasilense to fix nitrogen on pectin, chitin and carboxymethyl cellulose. The activity of nitrogen fixation by A. brasilense in the case of single and combined cultures with Trichoderma (using dry encapsulated beads) into the sterile soil increased with the addition of carbon source. Most of inoculations with free or alginate macrobead formulations of T. harzianum and/or A. brasilense showed significant increase in the growth parameters of tomato seedlings. The root system grew more profusely in the case of all seeds treated with A. brasilense. The growth parameters of Az/T24-treated seeds using dry coimmobilized macrobeads were higher than those of the untreated control. Moreover, the effect was improved significantly in soil enriched with different C sources. Enhanced tomato seedling growth after the co-inoculation could be due to the synergistic effect of both Trichoderma and Azospirillum. Finally, co-inoculation with Azospirillum and other microorganisms is one of the major frontiers of Azospirillum technology and perhaps the main area for future applications.

Purification and properties of a collagenolytic protease produced by Bacillus cereus MBL13 strain.

Abstract: Summary A novel collagenase-producing bacterium has been isolated and identified as Bacillus cereus MBL13. From the culture supernatant of B. cereus MBL13 grown on bone collagen as the sole carbon and nitrogen source, an extracellular protease with novel property of hydrolyzing waste animal bones was purified. The molecular mass of the purified collagenolytic protease was estimated to be (38.0±1.5) kDa. As determined by amino acid analysis, it had high contents of asparagine, lysine and serine. The optimum temperature and pH for the collagenase activity were 40 °C and pH=8.0, respectively. The results of the effects of some metal ions, inhibitors and protein substrates suggested that the purified collagenolytic protease is a member of the metalloproteases. Type I collagen (the typical collagen in animal bone) was used as the substrate for determination of Michaelis-Menten kinetics. The obtained Km value was (1.31±0.05) g/L and the corresponding vmax value was (12.54±2.5) mmol/min. The study assumes that the collagenolytic protease purified from B. cereus MBL13 strain could be applied in the hydrolysis of waste animal bones.

Bioethanol Production from Raw Juice as Intermediate of Sugar Beet Processing: A Response Surface Methodology Approach

Abstract: Summary Response surface methodology (RSM) was used for selecting optimal fermentation time and initial sugar mass fraction in cultivation media based on raw juice from sugar beet in order to produce ethanol. Optimal fermentation time and initial sugar mass fraction for ethanol production in batch fermentation by free Saccharomyces cerevisiae cells under anaerobic conditions at the temperature of 30 °C and agitation rate of 200 rpm were estimated to be 38 h and 12.30 % by mass, respectively. For selecting optimal conditions for industrial application, further techno-economic analysis should be performed by using the obtained mathematical representation of the process (second degree polynomial model). The overall fermentation productivity of five different types of yeast was examined and there is no significant statistical difference between them.

Production of a fermented solid containing lipases of Rhizopus microsporus and its application in the pre-hydrolysis of a high-fat dairy wastewater.

Abstract: Summary The filamentous fungus Rhizopus microsporus CPQBA 312-07 DRM was grown in solid-state cultivation and the fermented solid produced was used to hydrolyze triacylglycerols in a high-fat dairy wastewater. For the solid-state cultivation, a mixture of sunflower seed meal and sugarcane bagasse (1:3 by mass on dry basis) was selected. After 18 h of culture, the fermented product had an activity, measured titrimetrically against triolein, of 26 U per gram of dry solids. This substrate mixture does not suffer from compaction and therefore can be used in large scale solid-state cultivation bioreactors. When used to pretreat a high-fat dairy wastewater, with an oil and grease level above 1300 mg/L, the fermented solid reduced the oil and grease level to below 300 mg/L after 72 h at 35 °C. Further work is required to improve the production of lipolytic activity in the solid-state cultivation step and to find the optimum pretreatment time in the wastewater pretreatment step.

Biocatalytic process for production of α-glucosylglycerol using sucrose phosphorylase.

Abstract: Summary Glycosylglycerols are powerful osmolytes, produced by various plants, algae and bac-teria in adaptation to salt stress and drought. Among them, glucosylglycerol (2- O -a- D -glu-copyranosyl- sn -glycerol; GG) has attracted special attention for its promising applicationas a moisturizing agent in cosmetics. A biocatalytic process for the synthesis of GG as in-dustrial fine chemical is described in which sucrose phosphorylase (from Leuconostoc me-senteroides ) catalyzes regioselective glucosylation of glycerol using sucrose as the donorsubstrate. The overall enzymatic conversion, therefore, is sucrose+glycerol®GG+ D -fructose.Using a twofold molar excess of glycerol acceptor in highly concentrated substrate solu-tion, GG yield was 90 % based on ³250 g/L of converted sucrose. Enzymatic GG produc-tion was implemented on a multihundred kg-per-year manufacturing scale, and a com-mercial product for cosmetic applications is distributed on the market under the nameGlycoin ® . Technical features of the biotransformation that were decisive for a successfulprocess development are elaborated. Stabilization of proteins is another interesting field ofapplication for GG.

Exopolysaccharide Production and Prevention of Syneresis in Starch Using Encapsulated Probiotic Lactobacillus plantarum

Abstract: Summary Encapsulation of probiotic bacteria with a matrix can increase their survival rate by protecting them from adverse conditions and at the same time without affecting the production of metabolites. An effort has been made to encapsulate the probiotic Lactobacillus plantarum using calcium alginate. Box-Behnken model of response surface methodology (RSM) was employed in the optimization of major encapsulation conditions such as concentration of sodium alginate, calcium chloride and curing time. The second-order quadratic model with the optimum conditions (sodium alginate 2 % (by mass per volume), calcium chloride 0.5 M and curing time 3 h) resulted in a maximum titre of (0.9±0.1) g/L of exopolysaccharides (EPS) at 72 h. The nearness of the coefficient of determination (R 2 =0.97) to 1 ensures the satisfactory adjustment of the quadratic model to the experimental data. The efficiency of EPS production by encapsulated cells was compared with free cells. The efficacy of secreted EPS in the prevention of syneresis in starch was investigated.

Purification and characterization of antioxidant peptide from sunflower protein hydrolysate.

Abstract: Summary Sunflower proteins were hydrolyzed with Flavourzyme for the production of antioxidant peptide. DEAE-Sepharose Fast Flow, Sephadex G-25 gel filtration chromatography and reversed-phase HPLC were consecutively employed to purify a novel sunflower antioxidant peptide, and the ability to inhibit the autoxidation of pyrogallol was expressed as the antioxidative activity of the peptide. The amino acid sequence was identified as Ala-Cys-Ala-His-Asp-Lys-Val by a Q-Tof2 mass spectrometer. This novel peptide exhibited a high antioxidative activity of 79.42 U/mL, which is expected to protect against oxidative damage in living systems in relation to aging and carcinogenesis. Higher antioxidative activities were presumed mainly due to the presence of hydrophobic amino acids in its sequence.