菊粉研究的回顾与展望

菊粉作为一种天然功能性食品配料,已在欧美国家得到了广泛应用。近几年,中国的菊粉市场逐渐兴起。文中综述了菊粉的来源、理化性质和生理功能;介绍了菊粉在食品工业中的应用情况及其安全性评价;对比分析了菊粉在国内国外的生产加工情况;展望了菊粉的发展前景。     

Growth and Viability of Commercial Bifidobacterium spp in Skim Milk Containing Oligosaccharides and Inulin

Two commercial strains of Bifidobacterium spp (Bf ‐1 and Bf ‐6) were cultured in 12% (w/w) reconstituted nonfat dry milk (NDM) containing 0, 0.5, 1.0, 3.0, or 5.0% (w/v) fructooligosaccharide (FOS), galactooligosaccharide (GOS), and inulin. Inoculated samples were incubated anaerobically at 37° for 48 h. Growth and activity of the cultures in the presence of FOS, GOS, and inulin were determined. Viability of each strain was assessed after 4 weeks of refrigerated storage at 4°. Growth promotion, enhancement of activity and retention of viability were greatest when Bifidobacterium Bf‐1 and Bf‐6 were grown in the presence of FOS followed in a descending order by GOS and inulin. The effects of oligosaccharides and inulin increased with increasing carbohy drate concentration and was maximal at 5% (w/v).     

长双歧杆菌BBMN68 对便秘模型小鼠的通便作用

目的：研究长双歧杆菌活菌BBMN68 活菌液对便秘模型小鼠的润肠通便作用。方法：将Balb/c 雄性小鼠随机分为空白组、模型组、阳性对照组和3 个剂量的给药组。给药组分别经口给予低、中、高剂量(1 × 107、1 × 108、1 × 109CFU/mL)的长双歧杆菌BBMB68 活菌液0.1mL/(kg·d)(以体质量计);空白组和模型组给予0.1mL/(kg·d)的质量分数10% 的脱脂奶溶液;阳性对照组给予1 × 108CFU/mL 动物双歧杆菌菌悬液0.1mL/(kg·d)。用复方地芬诺酯制造小鼠便秘模型,建模后各组分别给药,观察各组小鼠的首次排黑便时间、5h 内排便粒数和质量,测定粪便含水量和小肠墨汁推进率。结果：长双歧杆菌BBMN68 给药7d,可明显改善便秘小鼠首次排黑便时间、增加排黑便粒数和质量;长双歧杆菌BBMN68 给药15d 可显著提高便秘小鼠小肠墨汁推进率。表明长双歧杆菌BBMN68 具有润肠通便功能。     

Effects of modified atmosphere packaging conditions on quality preservation of powdered infant formula

The effect of different modified atmospheres (100% N₂, 100% CO₂, 70% N₂/30% CO₂, 50% N₂/50% CO₂, and air) on the quality preservation of powdered infant formula was investigated by a storage test at 30°C. Metal can packages of 400 g per unit were stored for 493 days with periodic measurements of package gas composition and product quality attributes, which included peroxide value (POV), pH, titratable acidity, bifidobacteria count, hydroxymethylfurfural content, surface colour, and solubility. In the air package, POV as an oxidative quality index increased highly along with oxygen concentration decrease, reaching a maximum of 58.7 meq/kg lipid at 350 days. Compared with the air package, POV increase of the product was significantly lower, with all the O₂‐excluded modified atmosphere packages showing a maximum of 28.5 to 29.3 meq/kg at 350 days. Packages of high CO₂ concentration experienced a pH decrease and an acidity increase of the stored product caused by dissolution of CO₂. The count of bifidobacteria in the product was maintained higher after 119 days in the package of 100% CO₂ than in the other packages. Hydroxymethylfurfural content showed a slight increase after an initial period of slight decrease, with little difference among the package treatments. There were no significant changes in product solubility and surface colour during storage. Considering that the high CO₂ atmosphere helps the survival of bifidobacteria and protects the product from oxidation without negative effects on the other quality attributes, it is suggested for use in packaging of powdered infant formula.     

Invited review: Proteomics of milk and bacteria used in fermented dairy products: From qualitative to quantitative advances

Proteomics is a powerful tool that can simultaneously analyze several hundred proteins in complex mixtures, either through the use of high-resolution 2-dimensional gel electrophoresis or by mono- and multi-dimensional liquid chromatography coupled with mass spectrometry. Since the last review in 2005, proteomics has mainly been applied to describe minor proteins in the bovine milk fat globule membrane and soluble proteins in human colostrum. At least 130 new minor proteins have been identified. These proteins play roles in cell signaling, host defense, and transport as suggested by sequence homology. Proteomic approaches have also been applied to milk of other species such as donkey, horse, and marsupial. Peptides produced in food matrices that can exhibit functional or bioactive properties have been identified as have the proteases leading to their release in situ. However, the most spectacular proteomic development has been in the field of bacteria used in dairy products. Proteomics has resulted in the establishment of reference maps to detect strain-to-strain variations and to elucidate the mechanisms of in vitro and in vivo adaptation to environmental conditions. Proteomic analysis of bacteria entrapped in cheese has been achieved and revealed which predominant metabolic pathways are active depending on the strain. Proteomic approaches are often evoked as time-consuming procedures that provide a list of identified proteins without efficient quantification of each one. New quantitative proteomic methods have emerged and the most promising ones and their application to dairy products and bacteria will be presented.     

Chemical Characterization of Tomato Juice Fermented with Bifidobacteria

Abstract: The objective of this research was to characterize the chemical properties of tomato juice fermented with bifidobacterial species. Tomato juice was prepared from fresh tomatoes and heated at 100 °C prior to fermentation. Bifidobacterium breve, Bifidobacterium longum, and Bifidobacterium infantis were inoculated in tomato juice and kept at 35 to 37 °C for up to 6 h. Fructooligosaccharide (FOS) was added to tomato juice prior to fermentation. The analyses for brix, total titratable acidity (TTA), pH, color, and lycopene content were conducted to characterize tomato juices fermented with bifidobacterial species. Heat treatment of tomato juice did not cause any significant changes in brix, pH, and TTA. Only the redness of tomato juice was significantly increased, as the heating time increased to 30 min. The tomato juices fermented with B. breve and B. longum exhibited significant decreases in pH (3.51 and 3.80, respectively) and significant increases in TTA (13.50 and 12.50, respectively) (P < 0.05). B. infantis did not cause any significant change in the chemical properties of tomato juice. The addition of FOS further improved the fermentation of tomato juice by bifidobacterial species. The lycopene contents of tomato juice were significantly increased from 88 to 113 μg/g by heat treatment at 100 °C (P < 0.05), however did not exhibit any significant change after fermentation with bifidobacterial species.     

Viability and Activity of Bifidobacteria During Refrigerated Storage of Yoghurt Containing Mangifera pajang Fibrous Polysaccharides

Abstract: The viability and activity of Bifidobacterium pseudocatenulatum G4, B. longum BB 536 and yoghurt cultures (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) were studied in yoghurt containing 0.75%Mangefira pajang fibrous polysaccharides (MPFP) and inulin. Growth of probiotic organisms, their proteolytic activities, the production of short chain fatty acids (lactic, acetic and propionic) and the pH of the yoghurt samples were determined during refrigerated storage at 4 °C for 28 d. B. pseudocatenulatum G4 and B. longum BB 536 showed better growth and activity in the presence of MPFP and inulin, which significantly increased the production of short chain fatty acids as well as the proteolytic activity of these organisms. Practical Application: This is the first study reported on produce synbiotic yoghurt as a functional food for specified health uses contains bifidobacteria and M. pajang fibrous polysaccharides. M. pajang fibrous polysaccharides can be used as a prebiotic particularly in dairy products to increase the viability and activity of bifidobacteria which can be used as probiotic to exert health benefit to the human by yoghurt that is considered common use in society; thus, the benefits of synbiotic yoghurt are readily accessible to the member of society.     

Reduction of catechin,rutin, and quercetin levels by interaction with food‐related microorganisms in a resting state

Flavonoids are plant secondary metabolites abundant in foods and beverages of plant origin. These compounds are free radical scavengers and their consumption is linked to reduced incidence of coronary heart disease. In this study, two wine‐related microorganisms and one probiotic bifidobacteria strain were examined for their ability to absorb and/or transform the common flavonoids: quercetin, rutin, and catechin. Flavonoid absorption and/or transformation was determined using a resting cell assay (RCA) combined with high‐performance liquid chromatographic detection of the flavonoid losses. RCAs with Pediococcus pentosaceus ATCC 25745, Saccharomyces cerevisiae ATCC 36026, and Bifidobacterium longum DJO10A resulted in losses of rutin and quercetin. Further analysis of cell pellets indicated that, unlike rutin and catechin, most of the quercetin present in the assay was transported/adsorbed only into metabolically active cells. In 24 h the net quercetin loss from the resting cells of P. pentosaceus, S. cerevisiae, and B. longum was 21.3%, 27.1%, and 63.4%, respectively. These results suggest that these microorganisms, which are frequently present or added to food products, can decrease the overall concentration of quercetin, either through absorption or transport into the cell. The implications for the overall bioavailability of quercetin in humans remain to be determined. Copyright © 2006 Society of Chemical Industry     

Effects of fructooligosaccharide and whey protein concentrate on the viability of starter culture in reduced-fat probiotic yogurt during storage

ABSTRACT:  Viability of yogurt starter cultures and Bifidobacterium animalis was assessed during 28 d storage in reduced-fat yogurts containing 1.5% milk fat supplemented with 1.5% fructooligosaccharide or whey protein concentrate. These properties were examined in comparison with control yogurts containing 1.5% and 3% milk fat and no supplement. Although fructooligosaccharide improved the viability of Streptococcus thermophilus , Lactobacillus delbrueckii subs. bulgaricus, and Bifidobacterium animalis , the highest growth was obtained when milk was supplemented with whey protein concentrate in reduced-fat yogurt ( P < 0.05). Supplementation with 1.5% whey protein concentrate in reduced-fat yogurt increased the viable counts of S. thermophilus , L. delbrueckii subs. bulgaricus, and B. animalis by 1 log cycle in the 1st week of storage when compared to control sample. Similar improvement in the growth of both yogurt bacteria and B. animalis was also obtained in the full-fat yogurt containing 3% milk fat and no supplement. Addition of whey protein concentrate also resulted in the highest content of lactic and acetic acids ( P < 0.05). A gradual increase was obtained in organic acid contents during the storage.     

Comparative analysis of an intestinal strain of Bifidobacterium longum and a strain of Bifidobacterium animalis subspecies lactis in Cheddar cheese

Bifidobacteria cultures were incorporated into Cheddar cheeses to conduct a comparative analysis between the commercially available strain Bifidobacterium animalis ssp. lactis Bb-12 and the wild-type intestinal isolate, Bifidobacterium longum DJO10A. They were incorporated as starter adjuncts in separate vats and as a mixed culture, and survival through manufacturing and cheese ripening was assessed. For cheese using only Bb-12, the cells may have grown during cheese manufacture as 133% of the inoculum was incorporated into the cheese, resulting in 8.00 log cfu/g. Counts remained high during ripening showing less than 1 log decrease over a 12-mo period. For cheese using a mixed culture of Bb-12 and DJO10A, both strains were incorporated at much lower levels: 3.02 and 1.11%, respectively. This resulted in cheese with 6.00 and 5.04 log cfu/g for Bb-12 and DJO10A, respectively. Bifidobacteria survival rates were low, most likely due to the moisture of the cheese being below 38%. The Bb-12 demonstrated almost 100% viability during ripening. Numbers of DJO10A started to decline after 2 mo of ripening and dropped below the level of detection (2 log cfu/g) after 4.5 mo of ripening. Neither DJO10A nor Bb-12 fortified cheeses produced detectable amounts of organic acids during ripening other than lactic acid, indicating the lack of detectable metabolic contribution from bifidobacteria during cheese production and ripening such as production of acetic acid. To determine if sublethal stresses could improve the viability of DJO10A, 2 more vats were made, 1 with DJO10A exposed to sublethal acid, cold, and centrifugation stresses, and 1 exposed to none of these stresses. Although stress-primed DJO10A survived cheese manufacture better, as 72.8% were incorporated into the cheese compared with 41.1% of the unprimed, the statistical significance of this difference is unknown. In addition, the difference in moisture levels in the cheese cannot be excluded as influencing this difference. However, the rate of decline during ripening was similar for both. After 6 mo of ripening, cell counts in cheese were 4.68 and 4.24 log cfu/g for primed and unprimed cultures, respectively. These results suggest that whereas priming bifidobacteria with sublethal stresses before incorporation in a cheese fermentation may improve the number of viable cells that get incorporated into the cheese, it does not affect viability during cheese ripening.