Effect of flow rate and acid molarity on redox potential modulation during electroreduction of milk and simulated milk aqueous mineral phase

Electroreduction of milk is an efficient process to decrease the ORP of milk. However, the changes induced in milk are reversible and fouling is formed at the membrane surface. Results obtained showed that ORP reduction was more important when a flow rate of 300 ml/min was used in comparison with a flow rate of 100 ml/min. Moreover, at the higher flow rate, less fouling was observed on the membrane surface than at 100 ml/min. However, it appeared from the calculation of mass equivalent migrated that parameters studied (flow rate and acid concentration) did not have a direct influence on the electroreduction process but on the system resistance. This study is the first to our knowledge to show that in storage conditions where the gaseous exchanges and especially the oxygen are limited, it is possible to maintain during seven days a negative ORP in electroreduced milk.     

Determination of flavonoids by LC/MS and anti-inflammatory activity in Moringa oleifera

Moringa oleifera is an important multipurpose tropical tree under-recognized for its nutritional and medicinal properties. Leaves of moringa collected from sub-Sahara Africa were analyzed for phenolic components by HPLC–UV–MS. Twelve flavonoids were identified, including quercetin and kaempferol glucosides and glucoside malonates as major constituents. To facilitate quantitative analysis, acid hydrolysis during extraction of moringa samples was employed to convert the conjugates into their respective flavonoid aglycones, allowing accurate quantitation of total flavonoids as aglycones. Validation of the method demonstrated recoveries ranging from 92.6% to 107.5% for the two analytes. Using this method, total flavonoids from moringa collected from Ghana, Senegal and Zambia were determined and their content ranged from 0.18% to 1.64% (g/dry weight) across the respective environment or country of production and by variety. Moringa was found to exhibit anti-inflammatory activity of constituents-rich varieties. As flavonoid malonates are among the major constituents in the original plant material, a study examining thermal stability of flavonoid malonyl derivatives showed that these compounds were not thermally stable and easily cleaved to yield their respective flavonoid glycosides.     

Bioavailability and antioxidant potential of rooibos flavonoids in humans following the consumption of different rooibos formulations

In a complete crossover design, a human study with twelve healthy male volunteers has been conducted using a placebo and different rooibos drinks (rooibos tea and an isolated active fraction) from unfermented rooibos (Aspalathus linearis). Blood and urine samples were collected before and up to 24 h after consumption of the drinks.     

超声波辅助酶法提取香菇柄中总黄酮的工艺优化

目的对采用超声波辅助酶法提取香菇柄中黄酮类化合物的工艺进行优化,为进一步开发香菇柄资源提供依据。方法以总黄酮得率为指标,通过单因素试验研究乙醇体积分数、超声时间、超声功率及酶用量对黄酮类化合物得率的影响,利用响应面分析法对影响黄酮类化合物得率的上述4个因素进行优化。结果最佳提取工艺参数为:乙醇体积分数75%、超声时间20 min、超声功率280 W、酶用量0.012 mg。在此条件下,通过3次验证实验,测得黄酮类化合物的得率为1.673 mg/g,实际值与理论值基本吻合。结论采用响应面分析法优化超声波辅助酶法提取香菇柄中的黄酮类化合物的工艺具有可行性。     

用系统仿真评估酒店餐厅设施的利用状态

叙述了利用CSIMAN系统仿真技术建立一个餐厅仿真系统的方法.在实际数据的抽样基础上,对餐厅系统的设备数量及种类进行了模拟仿真,同时根据CSIMAN仿真系统中的资源利用率NR(I)和实体排队长度NQ(I),得出了合理的设备配置及数量,确定了餐厅的最佳利用状态.     

Dietary flavonoids: a novel strategy for the amelioration of cognitive impairment through intestinal microbiota

The chances of people suffering from cognitive impairments increase gradually with age. Diet and lifestyle are closely related to the occurrence and development of cognitive function. Dietary flavonoid supplementation has been shown to be one of the protective factors against cognitive decline. Flavonoids belong to a class of polyphenols that have been proposed for the treatment of cognitive decline. Recent evidence has shown that intestinal flora in the human body can interact with flavonoids. Intestinal microbiota can modify the chemical structure of flavonoids, producing new metabolites, the pharmacological activities of which may be different from those of the parent; meanwhile, flavonoids and their metabolites can, in turn, regulate the composition and structure of intestinal flora. Notably, intestinal flora affect host nervous system activity through the gut-brain axis, ultimately causing changes in cognitive function. This review therefore summarizes the interaction of dietary flavonoids and intestinal flora, and their protective effect against cognitive decline through the gut-brain axis, indicating that dietary flavonoids may ameliorate cognitive impairment through their interaction with intestinal microbiota. © 2022 Society of Chemical Industry.     

In vitro antioxidant and antimicrobial activities of the extract of Pericarpium Citri Reticulatae of a new Citrus cultivar and its main flavonoids

To provide the base for the application of a new cultivar of Citrus reticulata Blanco, whose family is Rutaceae, a flavonoid extract of Pericarpium Citri Reticulatae (FEPCR), the dried rind of the ripe citrus, was obtained with 80% aq. ethanol. Total flavonoid content of FEPCR was determined by a colorimetric method. Total phenol content was estimated as gallic acid equivalents. The major constituents of FEPCR, including Hesperidin, Nobiletin and Tangeretin, were determined by HPLC analysis. The antioxidant activities of FEPCR, Hesperidin, Nobiletin and Tangeretin were evaluated by various antioxidant assays, including DPPH scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and reducing power. All samples showed antioxidant activities to some degree in all the tested methods. In addition to the antioxidant activity, the antimicrobial assay was measured as well. Six strains of microorganisms including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Salmonella typhi and Enterobacter cloacae were used in the tests. FEPCR and Hesperidin displayed a broad antimicrobial spectrum and exerted antimicrobial effects in antimicrobial tests. But Tangeretin and Nobiletin exhibited low antimicrobial activities.     

Comparative analysis of total phenolic content, antioxidant activity, and flavonoids profile of fruits from two varieties of Brazilian cherry (Eugenia uniflora L.) throughout the fruit developmental stages

A better characterization of the flavonoids profile and antioxidant activity of Brazilian cherry fruits is expected to significantly increase their marketing appeal. Fruits at the green stage presented the highest antioxidant activity, measured as DPPH scavenging activity (17.18 and 18.13 mmol Trolox equivalents/100 g dried fruits for the red and purple varieties, respectively), and total phenolic content (4.14 and 5.81 g of ferulic acid equivalents/100 g dried fruit for the red and purple varieties, respectively), as well. Use of tandem mass spectrometry allowed the identification of myricetin 3-O-hexoside, myricetin 3-O-pentoside, myricetin 3-O-rhamnoside, quercetin 3-O-hexoside, quercetin 3-O-pentoside, quercetin 3-O-rhamnoside, and myricetin deoxyhexoside-gallate in both varieties of Brazilian cherry, regardless the developmental stage. Our data indicate that Brazilian cherry fruits are rich in natural antioxidants that might be more widely used by both, the general population and the food industry as a source of bioactive human health promoter phytochemicals.     

Antiradical activity,nutritional potential and flavonoids of the cladodes of Opuntia monacantha (Cactaceae)

This work reports the nutritional potential and the antiradical activity of the cladodes of the Brazilian Opuntia monacantha Haw. (Cactaceae), as well the isolation of kaempferol and isorhamnetin through activity-guided fractionation from its active MeOH extract. TLC, HPLC-DAD and NMR techniques were used to detect and identify the compounds. The water (91.1%), ash, protein, fibre and lipid contents (15.0, 5.4, 18.5 and 1.4 g/100 g, respectively) were shown to be quite similar to the mean values of other Opuntia spp., some widely used as food and forage. The antioxidant activity of their MeOH extract and of its n-hexane, EtOAc and n-BuOH fractions was assessed by measuring the ability of the fractions to scavenge DPPH radical, showing an activity enhancement for the fractions in comparison to the crude MeOH extract. The well-known free-radical scavenging activity of the isolated flavonoids reinforces the contribution of these compounds to the presented activity of the O. monacantha cladodes.     

Cymbopogon citratus leaves: Characterization of flavonoids by HPLC–PDA–ESI/MS/MS and an approach to their potential as a source of bioactive polyphenols

Leaves from cultivated Cymbopogon citratus were extracted with methanol, 80% aqueous ethanol and water (infusion and decoction) and the extracts were assessed for their antiradical capacity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay; the infusion extract exhibited the strongest activity. Tannins, phenolic acids (caffeic and p-coumaric acid derivatives) and flavone glycosides (apigenin and luteolin derivatives) were identified in three different fractions obtained from an essential oil-free infusion, and a correlation with their scavenger capacity for reactive oxygen species was studied. The tannin and flavonoid fractions were the most active against species involved in oxidative damage processes. In the flavonoid fraction, representing 6.1% of the extract, thirteen compounds (O- and C-glycosylflavones) were tentatively identified by high performance liquid chromatography, coupled to photodiode-array and electrospray ionization mass spectrometry detectors (HPLC–PDA–ESI/MS), nine of which were identified for the first time in this plant, all of them being C-glycosylflavones (mono-C-, di-C- and O,C-diglycosylflavones). The potential beneficial and protective value of the identified polyphenols for human health is discussed.     

Induction of the cell cycle arrest and apoptosis by flavonoids isolated from Korean Citrus aurantium L. in non-small-cell lung cancer cells

This study investigated the anti-proliferative and apoptotic effect of flavonoids isolated from Korean Citrus aurantium L. using A549 lung cancer cells. Flavonoids potently inhibited of A549 cells in a dose-dependent manner, whereas flavonoids had a weak inhibitory effect on proliferation of WI-38 cells. Flow cytometry and Western blot analysis showed that flavonoids induced cell cycle arrest at the G2/M checkpoint by controlling the proteins expression level of cyclin B1, cdc2, cdc25c and p21^WAF1/CIP1. Also, flavonoids induced apoptosis through the regulation of the expression of caspases, cleaved PARP and Bax/Bcl-xL ratio. The activity of caspase-3 on A549 cells increased in a dose-dependent manner. These results clearly indicated that the anti-cancer effect of flavonoids on A549 cells follows multiple cellular pathways through G2/M arrest and the induction of apoptosis.     

Supercritical fluid extraction as a potential mitigation strategy for the reduction of acrylamide level in coffee

The removal of acrylamide from coffee through supercritical CO₂ extraction has been investigated for the first time. Two steps were performed: a pre-roasting treatment and a supercritical extraction process. The main aim of this first work was to investigate the feasibility of the process more than the impact of the treatment on the organoleptic properties of coffee. The efficiency of acrylamide removal was checked by measuring its content in the coffee beans before and after the supercritical treatment. The role of temperature, pressure, extraction time and the addition of a modifier (ethanol) was examined.     

试谈我国造纸行业的生命周期及现阶段企业应采取的战略措施

行业生命周期理论认为，行业在市场的演变历程可划分为投入期、成长期、成熟期，衰退期四个阶段。通过对国内造纸行业近10年的纸及纸板需求量分析，推导出目前该行业正处于成长－成熟期阶段，为企业制定适时、适势、适合的企业战略提供参考。     

The flavonoid paradox: conjugation and deconjugation as key steps for the biological activity of flavonoids

Flavonoids have been proposed to exert beneficial effects in the prevention of a large number of diseases, including cancer, cardiovascular disease, and neurodegenerative disorders. Paradoxically, despite the most representative flavonoid--quercetin--exerting biologically demonstrable systemic effects, it is not found in plasma after oral administration and its circulating metabolites show weak activity in vitro. The current available evidence indicates that quercetin is extensively metabolized into methylated and glucurono- and sulfo-conjugated metabolites, which are the plasma circulating forms; and glucurono-, but not sulfo-conjugates, can be hydrolyzed at the vascular level, yielding the parent aglycone which accumulates in tissues. Thus conjugation is a reversible process and, at least regarding the vasodilator and antihypertensive effects, the conjugation-deconjugation cycle appears to be an absolute requirement. Glucuronidated derivatives transport quercetin and its methylated form, and deliver to the tissues the free aglycone, which is the final effector.     

全面推行国际化战略促进企业快速发展--关于山东晨鸣纸业集团股份有限公司的报告

系统地阐述了山东晨鸣纸为集团实施国际化战略的背景、过程、措施及取得的效果.     

高产木聚糖酶嗜热子囊菌固体发酵条件与酶学性质

以本实验室从土壤中分离筛选到的一株高产木聚糖酶的嗜热子囊菌QS7-2-4为生产菌种,进行固体发酵产木聚糖酶的发酵条件研究,结果表明最佳产酶条件为:玉米芯:麸皮为7:3(w/w);最佳氮源为酵母膏和胰蛋白胨的混合氮源,添加量为1.5%;吐温-80添加量为0.5%,初始pH为7.2,培养基含水量为80%,250mL三角瓶装料量为8g,发酵温度50℃,发酵时间72h,该条件下木聚糖酶产量达27952U/g干基。该酶最适反应温度为75℃,最适反应pH为4.5,在70℃以下具有良好的稳定性,在室温下储藏150d仍然保留87%的活性。     

Assessing the validity of a niche strategy model in predicting the potential and success of niche markets and products

Companies can increase market share and profitability through the use of a niche market strategy. Parrish examined how companies use a niche market strategy and developed the Parrish Niche Strategy Model. This paper presents results of a study testing the model in terms of: (1) predicting the potential of a niche market and/or product and (2) predicting the success of a niche market and/or product. In order to test the model, deductive logic was used to develop questions that would gather quantitative data related to market potential strategies and success variables. In order to determine the importance of variables in relation to predicting the potential and success of a niche market and/or product, instrument questions were developed that utilized rank order scales. In addition, three-point Likert scales were used in order to determine the level of importance for each of the market potential and success variables. The sample consisted of fiber and yarn manufacturers, fabric manufacturers, apparel manufacturers and marketers, and retailers. Results indicate that the Parrish Niche Strategy Model was useful for gaging the potential and success of niche strategies, in terms of both product and market. This research was significant in that it tested the only existing model of niche strategies developed specifically for the textile industry. In addition, this study focused on bottomweights, which represents a significant domestic consumption market for the US textile supply chain.     

Reuse potential of vegetable wastes (broccoli,green bean and tomato) for the recovery of antioxidant phenolic acids and flavonoids

The aim of this study was to evaluate the potential use of crop wastes (stems and leaves) from broccoli, beans and tomato to extract antioxidant polyphenols. Two different methods of extraction were performed: ultrasound (40 kHz) and conventional with 70 °C. In both methods, alkaline and acidic solvents were used. The polyphenol composition was assessed by HPLC‐DAD/UV‐VIS, and the 2,2‐diphenyl‐1‐picrylhydrazyl assay was used to measure the antioxidant activity. The results showed a significant variation of polyphenol composition and antioxidant activity with the type of sample, pH of solvent and extraction method. Also it was possible to observe that acidic methanol and 70 °C enables the extraction of significant amounts of phenolic acids and flavonoids. Based in our results , broccoli, green bean and tomato wastes can be used to extract antioxidant polyphenols, and the use of such wastes to extract polyphenols can be an opportunity to develop an environmental friendly management's systems creating incoming for producers and agro‐food sector.     

Partial characterization of lipases produced by a newly isolated Penicillium sp. in solid state and submerged fermentation: A comparative study

The aim of this research was the partial characterization of enzymatic extracts produced by a newly isolated Penicillium sp. in submerged (SmF) and solid state fermentation (SSF). The partial characterization of the crude enzymatic extract obtained by SSF and SmF systems showed optimum activity at pH 5.5 and 47 °C, and pH 7.0 and 37 °C, respectively (15.17 U/mL and 11.28 U/mL). The crude enzymatic extracts obtained by SmF and SSF presented the best stability at pH from 4.9 to 8.5 and temperature from 25 °C to 35 °C and pH 7.0 and 25 °C, respectively. These results confirm the interesting potential of SSF, because, besides the higher activities obtained in this system, the half-life time at 25 °C was higher than that observed for the lipase extract obtained in the SmF system.