Study on enhanced absorption of phenolic compounds of Lactobacillus‐fermented turmeric (Curcuma longa Linn.) beverages in rats

Lactobacillus plantarum, used as starter culture to produce turmeric beverages, was isolated and screened from the turmeric rhizomes. Fermented turmeric beverages were evaluated for its antioxidant activity using 2‐2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging activity and ferric‐reducing antioxidant power (FRAP) assay. The fermentative process resulted in an increase in antioxidant activity. The absorption of turmeric powder, turmeric powder‐mixed encapsulated probiotic (TP) and encapsulated fermented turmeric beverage (TB) in rats was measured in terms of antioxidant activity in the plasma. Plasma antioxidant concentration was higher in rats administrated fermented turmeric beverage than other turmeric products, at all the time points. The maximum concentration (C_max) value and area under the plasma concentration versus time curve (AUC) were higher in the rat administered with TB. The value was lower in the plasma of rats administered with turmeric powder and TP. The results indicated that the fermentative turmeric possesses better bioavailability and in accordance with the concentrations of polyphenolic compounds in the rat plasma.     

The use of antifungal oat‐sourdough lactic acid bacteria to improve safety and technological functionalities of the supplemented wheat bread

In the present study, predominant lactic acid bacteria (LAB) were isolated from oat sourdough. Then, the isolates were screened based on their in vitro antifungal activity. Subsequently, biotechnological capabilities of the selected LAB were evaluated in wheat bread supplemented with controlled fermented oat containing the isolate. Pediococcus pentosaceus was molecular identified as predominant antifungal isolate. Based on our results, fermented oat not only significantly (p < .05) reduced the mold expansion on the produced breads, but also improved the quality attributes of the product. Crumb porosity and antioxidant capacity of the supplemented bread revealed the positive effects of the isolate on textural and functional characteristics of the enriched bread. Wheat bread supplemented with controlled fermented oat had also the highest 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity compared to the other samples. Accordingly, the potential applications of P. pentosaceus isolate as profunctional starter culture in processing of mixed wheat‐oat sourdough bread were verified.     

Stevia‐fortified yoghurt: Stability,antioxidant activity and in vitro digestion behaviour

In this study, yoghurt samples were fortified with 0.25% and 0.5% freeze‐dried stevia extract (FSE). The control and stevia‐fortified yoghurts were evaluated and compared for the viability of the starter cultures, physicochemical properties, total phenolic content (TPC) and antioxidant activity throughout 30 days of storage. In addition, TPC and antioxidant activity were evaluated during in vitro gastrointestinal digestion. The results showed that the yoghurt matrix preserved the TPC, antioxidant capacity and total solids during storage, while the acidity, synaeresis and counts of the starter cultures of the final product were not significantly affected. However, addition of 0.5% FSE exerted a buffering effect on the system. After simulated digestion, the values of TPC and antioxidant activity of the fortified yoghurts increased in relation to the undigested fractions. These findings showed the feasibility of employing FSE as a functional ingredient in the manufacture of yoghurts with potential antioxidant properties.     

Survival of Escherichia coli O157:H7, nitrite content and sensory acceptance of low‐salt Chinese paocai fermented by screened lactic acid bacteria

Starter cultures of low‐salt Chinese paocai were screened from 135 lactic acid bacteria (LAB) by evaluating their antimicrobial activity and growth characteristics. Furthermore, the survival of Escherichia coli O157:H7, nitrite contents and sensory acceptability of the starter‐fermented paocai were evaluated. LAB BC92, which was identified as Lactobacillus pentosus, was used as a starter culture to produce paocai. In comparison with naturally fermented paocai, the disappearance time of E. coli O157:H7 in starter‐fermented paocai decreased from 5.29 to 3.82 days, and the maximum nitrite content decreased from 11.73 to 8.64 mg kg^?1, and the nitrite reduction time decreased from 4 to 3 days. In addition, starter fermentations were able to accelerate the flavour formation and shorten the paocai ripening period. The paocai that was fermented naturally and fermented by BC92 all had good sensory acceptance, and no significant difference (P > 0.05) was observed.     

Fundamental study on the effect of hydrostatic pressure treatment on the bread-making performance of oat flour

The use of sourdough in wheat and rye breads has been extensively studied; however, little is known about its potential effect when baking oat bread. Consequently, the impact of sourdough on oat bread quality was investigated. Two different sourdoughs were prepared from wholegrain oat flour without the addition of starter cultures, by continuous propagation at 28 (SD 28) or 37 °C (SD 37) until the composition of the lactic acid bacteria remained stable. The dominant LAB were identified by sequence analysis of the 16S rDNA isolated from pure cultures. LAB from SD 28 belonged to the species Leuconostoc argentinum, Pedicoccus pentosaceus and Weissella cibaria, while Lactobacillus coryniformis dominated SD 37. The isolated LAB were further used as starter cultures for the production of oat sourdoughs. Fundamental rheology revealed softening of the sourdoughs compared to non-acidified and chemically acidified controls, which could not be attributed to proteolytic activity. Incorporation of oat sourdough into an oat bread recipe resulted in significantly increased loaf-specific volume as well as improved texture, independent of addition level or sourdough type. Overall, the results of this study show that sourdoughs containing lactic acid bacteria isolated from oats have the potential to enhance oat bread quality.     

Jabuticaba (Myrciaria cauliflora) Seeds: Chemical Characterization and Extraction of Antioxidant and Antimicrobial Compounds

This study was aimed to assess the effect of time and temperature on the extraction of antioxidant compounds from jabuticaba seeds (Myrciaria cauliflora cv. Sabará), to optimize the solvent proportion (water, ethyl alcohol, and propanone), and to characterize the extract according to the chemical composition, antioxidant, and antimicrobial properties. Proximal composition, total phenolic content (TPC), antioxidant, and antimicrobial activities were analyzed. The optimized solvent ratio of 60% water and 40% propanone provided a mean TPC of 8.65 g GAE/100 g seeds and the antioxidant activity toward 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) was 82.79% ± 0.50%. Time and temperature parameters did not influence the yield of TPC. The gross seed extract was partially purified and both exhibited a high antioxidant activity and antimicrobial potential toward Gram‐positive and Gram‐negative bacteria. The purified jabuticaba seed lyophilized extract contained a higher (P < 0.05) TPC, o‐diphenols, flavonols, and antioxidant activity measured by the DPPH assay and total reducing capacity as compared to the gross lyophilized extract. Electrospray ionization coupled with tandem mass spectrometry (ESI‐MS/MS) data showed the presence of ellagitannins and ellagic acid in the extracts, which are probably the responsible for the antimicrobial and antioxidant activities.     

发酵肉制品中高抗氧化肉品发酵剂的筛选鉴定

为获得高抗氧化活性的天然肉品发酵剂,通过清除自由基、还原能力和抗脂质过氧化实验对来源于5种发酵肉制品中30株乳酸菌的发酵上清液、菌体细胞和胞内提取物的抗氧化活性进行研究,并按照肉品发酵剂的筛选标准对高抗氧化性的菌株进行筛选,鉴定出符合要求的菌株。结果表明:这30株乳酸菌具有不同的抗氧化能力且不同组分的抗氧化活性之间存在很大差异,发现菌株L23、L26和L28具有较高的抗氧化活性,其中L23符合肉品发酵剂的筛选标准,可作为天然高抗氧化性肉品发酵剂用于生产。经鉴定L23为希腊魏斯氏菌。     

Separation of Curcuminoids Enriched Fraction from Spent Turmeric Oleoresin and Its Antioxidant Potential

Abstract: The rhizomes of turmeric are processed to obtain oleoresin and subsequently curcuminoids are isolated. The mother liquor, after partial isolation of curcuminoids, known as spent turmeric oleoresin (STO), is considered as industrial waste. Curcuminoids enriched spent turmeric oleoresin (CSTO) is prepared by removal of nonantioxidant constituents, and investigated for its antioxidant potential using in vitro methods, and also the total curcuminoids and phenolic contents were determined. CSTO has a total phenolic content of 267.27 ± 5.75 mg GAE/g that is almost double the amount present in STO (118.3 ± 3.0 mg GAE/g). The total amount of curcuminoids in CSTO is found to be 39 ± 1.2%, whereas STO had 15 ± 2.0%. CSTO possessed radical scavenging activity of 84% at 50 μg/mL, antioxidant activity of 74% at 25 μg/mL, high antioxidant capacity, and moderate total reducing power. These results provide scope for utilization of CSTO/STO as natural antioxidant/preservative as well as colorant in various foods.     

Effects of inlet air temperature and spray rate of coating solution on quality attributes of turmeric extract coated rice using top-spray fluidized bed coating technique

The addition of natural antioxidants onto white rice kernel can improve its functionality. Curcuminoids that present in turmeric rhizomes possess high antioxidant activity and heat stability. The objective of this study was to investigate the effects of inlet air temperatures and spray rates of turmeric extract solution on quality attributes of the turmeric extract coated rice (TCR) using the top-spray fluidized bed coating technique. The experimental results have shown that inlet air temperature and spray rate of coating solution strongly affected the final moisture content and percentage of fissured kernel of TCR. Almost all of TCR kernels in the bed cracked when their final moisture content was lower than 11.8% wet basis. However, the head coated rice yield of fissured TCR slightly decreased from that of white rice. The color of TCR was uniform over the entire surface. Texture of cooked TCR insignificantly changed from that of uncoated sample. Increasing spray rate provided higher both total phenolic content (TPC) and total antioxidant capacity (TAC) whilst increasing inlet temperature yielded lower TPC but it did not affect TAC. Retentions of TPC and TAC of TCR after cooking remained higher than 90%.     

Probiotic potential of lactic acid bacteria from fermented Malaysian food or milk products

This study investigated the probiotic characteristics of lactic acid bacteria (LAB) isolated from 14 Malaysian fermented food or milk products. In total, 22.3% (121 of 542) of the LAB isolated from the local fermented products exhibited antibacterial activity against Micrococcus luteus. Twelve LAB that demonstrated better antibacterial activity against M. luteus as compared to a commercial strain Lactobacillus casei strain Shirota (LABPC) were selected for further characterisation. Based on 16S rRNA gene sequence, the LAB were identified as pediococci (seven) and lactobacilli (five). All 12 LAB showed bile tolerance, but only eight were acid tolerant at pH ≥ 3.0. The highest level of adhesion to HT‐29 cells was observed among the Lactobacillus sp. LAB 1 and 10. The LAB also showed antimicrobial activity against Escherichia coli and Staphylococcus aureus through the production of organic acids. LAB isolated from Malaysian fermented food and milk products, especially fermented tapioca, contains potential probiotic candidates.     

In vitro probiotic evaluation of potential antioxidant lactic acid bacteria isolated from idli batter fermented with Piper betle leaves

Lactic acid bacteria isolated from food sources can be introduced as probiotics because of their health‐promoting and nonpathogenic characteristics. Eight lactic acid bacteria from idli batter fermented with Piper betle leaves were selected to screen the antioxidant potential and biofilm‐forming ability. Five isolates exhibited good antioxidant potential and biofilm formation and showed antagonistic activity against the pathogenic biofilm‐forming Staphylococcus aureus. Further, in vitro probiotic properties of five isolates exhibited excellent acid tolerance, bile tolerance, simulated gastrointestinal juice tolerance, auto‐aggregation and co‐aggregation and hydrophobicity and showed resistance to antibiotics such as ciprofloxacin, nalidixic acid, norfloxacin and colistin. Isolates also showed positive bile salt hydrolase activity, cholesterol assimilation, β‐galactosidase production and mucin binding ability. The isolate KJBB10 exhibited good adhesion and pathogen exclusion percentage with human colon cancer cells (HCT‐15 and HT‐29). Hence, the isolates KJBB10, KJBB56 and KJBC06 can be used as beneficial probiotic starter cultures for the formulation of functional foods.     

Isolation and identification of exopolysaccharide producer lactic acid bacteria from Turkish yogurt

Lactic acid bacteria (LAB) were isolated from traditional yogurt samples and genotypic characterization of these isolates revealed the presence of 21 distinct LAB strains belonging to Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Leuconostoc mesenteroides, and Lactobacillus plantarum as new LAB strains. Determination of the exopolysaccharide (EPS) production characteristics of the selected strains of each species revealed that all strains possessed at least one gene required for both homopolymeric‐ and heteropolymeric‐type EPS production. Structural analysis of the EPSs showed that L. delbrueckii subsp. bulgaricus Y39 and S. thermophilus Y102 produced heteropolymeric EPS containing glucose and galactose, whereas Leuc. mesenteroides Y35 and L. plantarum Y36 produced homopolymeric glucan‐type EPS. The level of EPS production in these strains was found to be in a similar range. These strains with EPS production characteristics are good candidates for future studies as new LAB for yogurt production.

Practical applications

Recent trends in yogurt production technology have led to an increased use of ropy starter cultures in yogurt production due to the technological roles of exopolysacharides (EPS) produced by these cultures. The main role of EPS in yogurt production is to improve the textural properties of yogurt as an in situ produced natural polymer. In addition to the yogurt starter cultures, use of adjunct cultures during production of yogurt is also of special interest to enhance the technological and nutritional characteristics of yogurt. Therefore, in this study, potential yogurt starter and adjunct cultures from traditional yogurt samples with EPS production characteristics were isolated. From these isolates, Lactobacillus delbrueckii subsp. bulgaricus Y39 and Streptococcus thermophilus Y102 produced heteropolymeric EPS containing glucose and galactose, whereas Leuconostoc mesenteroides Y35 and Lactobacillus plantarum Y36 produced homopolymeric glucan.     

Identification and molecular characterisation of lactobacilli isolated from traditional Koopeh cheese

This study was undertaken in order to phenotype and genotype wild‐type lactic acid bacteria isolated from Koopeh cheese of West Azerbaijan. Lactic acid bacteria (LAB) isolates were identified by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) and confirmed by phylogenetic analysis. Genotyping based on phylogenetic analysis of 16s rDNA gene revealed that LAB isolated from Koopeh cheese were mostly Lactobacillus plantarum as well as other species including Lactobacillus brevis, Entrococcus faecium and Enterococcus durans. It was concluded that a combined phenotypic and genotypic method could be used as a reliable technique for the identification and differentiation of LAB from dairy products.     

Purification and properties of cysteine protease from rhizomes of Curcuma longa (Linn.)

BACKGROUND: Turmeric rhizome (Curcuma domestica Linn.) contains proteases and has proteolytic activity. Curcumin from turmeric rhizomes has been used for healing manu ailments, including cancer have been used for healing many ailments, including cancer. The purpose of this study was to purify turmeric protease and to research their biochemical characteristics. RESULTS: Cysteine protease from C. domestica has been purified to homogeneity using acetone precipitation followed by preparatory native polyacrylamide gel electrophoresis (PAGE). This protocol resulted in six fold purification with 28% final recovery. The purified turmeric protease showed a prominent single peak and band on high‐performance liquid chromatography and sodium dodecyl sulfate–PAGE, respectively, and an estimated molecular weight of 43 KDa, and exhibited optimal activity between 37 and 60 °C. The protease activity of the turmeric protease was significantly inhibited by iodoacetic acid. The turmeric protease had higher alanine and glutamate content and cleaved synthetic peptides N‐Cbz‐Ile‐Pro and N‐Cbz‐Phe‐Leu in a time‐dependent manner. Peptide mass fingerprint using matrix‐assisted laser desorption/ionization–time of flight mass spectroscopy revealed peptide matches to proteasome subunit alpha type 3 of Oryza sativa ssp. japonica (Rice). The turmeric protease showed antifungal activity at 10 µg mL^?1 towards pathogens Pythium aphanidermatum, Trichoderma viride and Fusarium sp. CONCLUSION: Cysteine addition significantly activated turmeric protease. The protease inhibition test suggested that turmeric protease belonged to the cysteine type. The biochemical characteristics of turmeric protease described in this paper can provide useful information for potential end uses of turmeric protease for pharmaceutical industry applications such as therapeutics. Copyright © 2009 Society of Chemical Industry     

Antioxidant Activities and Phenolic Compounds of Several Tissues of Pawpaw (Asimina triloba [L.] Dunal) Grown in Korea

Pawpaw (Asimina triloba [L.] Dunal) possesses antioxidant compounds and strong inhibitors of cancer cells, and is widely cultivated in North America, Canada, and Korea. We analyzed the total phenolic and total flavonoid contents (TPC and TFC, respectively) of pawpaw plants grown in Korea and the antioxidant activities of their roots, twigs, leaves, and fruit with respect to 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) radical scavenging activity, 2,2′‐azino‐bis diammonium salt (ABTS) radical scavenging activity, ferrous (Fe²⁺) chelating ability, and nitrite scavenging activity. Pearson's correlation analyses revealed a linear correlation between TPC and antioxidant activities (r² >0.69). Root methanol extracts had higher TPC and antioxidant activities than other extracts, which was also consistent with those from the phenolic compounds found in those extracts. Therefore, antioxidant activities seem to depend on the TPC of each pawpaw tissue and pawpaw roots might be useful as a natural source of natural antioxidants.     

Lactobacillus plantarum AR501 Alleviates the Oxidative Stress of D‐Galactose‐Induced Aging Mice Liver by Upregulation of Nrf2‐Mediated Antioxidant Enzyme Expression

Lactic acid bacteria (LAB) have been used as ingredients of functional foods to promote health and prevent diseases because of their beneficial effects. This study aimed to investigate the antioxidative effects of LAB on the hepatotoxicity in D‐galactose‐induced aging mice. LAB were isolated from the traditional Chinese fermented foods and screened by the tolerance of hydrogen peroxide (H₂O₂). Male ICR (Institute of Cancer Research) mice were subcutaneously injected with D‐galactose for 5 weeks and then gastric gavage with LAB for 6 weeks. The results showed that Lactobacillus plantarum AR113 and AR501, and Pediococcu pentosaceus AR243 could tolerate up to 1.5 mM H₂O₂ in vitro, and they could live through simulated gastrointestinal tract (GIT) to colonizing the GIT of host. In vivo, oral administration of L. plantarum AR113 and AR501 improved the antioxidant status of D‐galactose‐induced oxidative stress mice such as alleviated liver damages and reduced abnormal activities of superoxide dismutase, glutathione peroxidase, and catalase to normal levels. In addition, L. plantarum AR501 markedly elevated the gene expression of nuclear factor erythroid‐2‐related factor 2 and upregulated the expressions of several antioxidant genes such as glutathione reductase, glutathione S‐transferase, glutamate‐cysteine ligase catalytic subunit, glutamate‐cysteine ligase modifier subunit, and NAD(P)H quinone oxidoreductase 1 in the liver of an aging mice. Therefore, L. plantarum AR501 could be a good candidate for producing antiaging functional foods.     

Identification of lactic acid bacteria isolated from oat sourdoughs and investigation into their potential for the improvement of oat bread quality

The use of sourdough in wheat and rye breads has been extensively studied; however, little is known about its potential effect when baking oat bread. Consequently, the impact of sourdough on oat bread quality was investigated. Two different sourdoughs were prepared from wholegrain oat flour without the addition of starter cultures, by continuous propagation at 28 (SD 28) or 37 °C (SD 37) until the composition of the lactic acid bacteria remained stable. The dominant LAB were identified by sequence analysis of the 16S rDNA isolated from pure cultures. LAB from SD 28 belonged to the species Leuconostoc argentinum, Pedicoccus pentosaceus and Weissella cibaria, while Lactobacillus coryniformis dominated SD 37. The isolated LAB were further used as starter cultures for the production of oat sourdoughs. Fundamental rheology revealed softening of the sourdoughs compared to non-acidified and chemically acidified controls, which could not be attributed to proteolytic activity. Incorporation of oat sourdough into an oat bread recipe resulted in significantly increased loaf-specific volume as well as improved texture, independent of addition level or sourdough type. Overall, the results of this study show that sourdoughs containing lactic acid bacteria isolated from oats have the potential to enhance oat bread quality.     

Characterization of Antibiotic Resistance Genes from Lactobacillus Isolated from Traditional Dairy Products

Lactobacilli are widely used as starter cultures or probiotics in yoghurt, cheese, beer, wine, pickles, preserved food, and silage. They are generally recognized as safe (GRAS). However, recent studies have shown that some lactic acid bacteria (LAB) strains carry antibiotic resistance genes and are resistant to antibiotics. Some of them may even transfer their intrinsic antibiotic resistance genes to other LAB or pathogens via horizontal gene transfer, thus threatening human health. A total of 33 Lactobacillus strains was isolated from fermented milk collected from different areas of China. We analyzed (1) their levels of antibiotic resistance using a standardized dilution method, (2) their antibiotic resistance gene profiles by polymerase chain reaction (PCR) using gene‐specific primers, and (3) the transferability of some of the detected resistance markers by a filter mating assay. All Lactobacillus strains were found to be resistant to vancomycin, but susceptible to gentamicin, linezolid, neomycin, erythromycin, and clindamycin. Their susceptibilities to tetracycline, kanamycin, ciprofloxacin, streptomycin, quinupristin/dalfopristin, trimethoprim, ampicillin, rifampicin, and chloramphenicol was different. Results from our PCR analysis revealed 19 vancomycin, 10 ciprofloxacin, and 1 tetracycline‐resistant bacteria that carried the van(X), van(E), gyr(A), and tet(M) genes, respectively. Finally, no transferal of the monitored antibiotic resistance genes was observed in the filter mating assay. Taken together, our study generated the antibiotic resistance profiles of some milk‐originated lactobacilli isolates and preliminarily assessed their risk of transferring antibiotic gene to other bacteria. The study may provide important data concerning the safe use of LAB.     

Development of fermented Hericium erinaceus juice with high content of L‐glutamine and L‐glutamic acid

Fermented plant beverages (FPB) with a high content of desirable principle components are served as functional foods from several years. Hericium erinaceus is famous for its antimicrobial, antioxidant, antihypertensive and antidiabetic nature. Accordingly, the current study was aimed to produce fermented H. erinaceus juice with a high content of L‐glutamine (Gln) and L‐glutamic acid (GA) through lactic acid bacteria (LAB) isolated from fermented Thai foods. LAB isolates were screened and identified the potent protease‐producing bacteria Enterococcus faecalis (G414/1) that facilitate the production of Gln and GA through protein hydrolysis. Box–Behnken design (BBD) and response surface methodology (RSM) were adapted for the optimisation of conditions for the increased production of Gln and GA during fermentation of H. erinaceus. We succeeded with an optimum concentration of cofactor (CaCl₂), pH and temperature for improved protease activity and subsequent Gln and GA production. The ability of isolated E. faecalis strain to produce Gln and GA was demonstrated in this study. Further, upstream processes like strain improvement and media optimisation will direct the way to produce enriched H. erinaceus based FPB.     

Antioxidant and tyrosinase inhibition properties of leaves and rhizomes of ginger species

Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) of leaves of 26 ginger species belonging to nine genera and three tribes were screened. For 14 species, TPC and AEAC of rhizomes were also assessed. Ferrous ion-chelating (FIC) abilities of leaves and rhizomes of eight species were compared. Leaves of five species of Etlingera were analysed for tyrosinase inhibition activity. Of the 26 species, leaves of Etlingera species had the highest TPC and AEAC. Eleven of the 14 species had significantly higher TPC and/or AEAC in leaves than in rhizomes. Values of leaves of Etlingera elatior and Etlingera maingayi were seven to eight times higher than those of rhizomes. In terms of FIC ability, six of the eight species clearly showed higher values in leaves than in rhizomes. The most outstanding was the FIC value of Alpinia galanga leaves which was more than 20 times higher than that of rhizomes. Of the five species of Etlingera, leaves of E. elatior displayed the strongest tyrosinase inhibition activity, followed by leaves of Etlingera fulgens and E. maingayi. Values of their inhibition activity were significantly higher than or comparable to the positive control. Besides promising tyrosinase inhibition ability, leaves of these three Etlingera species also have high antioxidant activity and antibacterial properties.