Proteic-anabolic capacity in rats--influence of the quality and quantity of dietary protein

The effect of quality (casein + 5% DL-methionine, normal or heated at 180 degrees C for 20 min) and quantity (4%, 6%, 10%, 15% and 20%) of dietary protein on food intake, weight increase and nitrogen retention, has been studied in both sexes weaning Nestle rats. Our results show that food intake, when expressed as g dry matter/100 g body weight and day, is not dependent on the quality and quantity of dietary protein. Weight increase goes up at a 10% dietary protein level. At higher protein levels (15% and 20%) values are only maintained. Protein quality do not cause any difference. Nitrogen retention goes up on increasing dietary protein level, with a maximum at 10% casein-methionine and 15% heated protein, being retention heated casein-methionine significantly lower. At a higher protein level, the maximal anabolic capacity for protein is maintained. Maximum Protein Productive Value (PPV) is obtained from diets containing 10% protein level (normal or heated). There is a significant decrease at higher protein levels (15% and 20%). The PPV of heated casein-methionine is lower than PPV of normal one at 6%, 10%, 15% and 20% protein levels. The results state that in our assays, in spite of the good quality of heated casein-methionine, its metabolic efficiency is below non heated protein values even when protein contribution is increased. We can assume that protein quantity is not a balancing factor for protein quality.     

Factors affecting the quality of Arabic bread — fermentation variables

The effect of finished dough temperature, fermentation time, and intermediate and final proving time on the quality of Arabic bread has been investigated. Statistical analysis of the loaf scores indicated that all these factors affect the bread quality, sometimes in several ways. Final proving time and its combined effect with dough temperature were most significant. Extension of final proving time had the advantage of producing blister-free Arabic bread and of improving the crust smoothness, evenness of layers and crumb texture, although darker crust and crumb colour resulted.     

凝乳酶的添加量对半硬质干酪品质影响研宄

研究凝乳酶的添加量对半硬质干酪品质的影响,以确定其最佳添加量.采用单因素试验设计,凝乳酶的添加量分别为2、2.5、3、3.5、4(g/100 kg牛奶).在其他工艺条件相同的情况下,分别加工一批干酪,然后测定成熟干酪的性能指标.结果表明,随着凝乳酶添加量的增加,干酪的感官评定值先增加,然后逐渐减低;干酪的硬度、pH4.6可溶性氮含量、游离氨基酸总量和水分含量逐渐增加,而pH值变化不大.以感官评定值为主指标,结合其他性能指标,确定凝乳酶的最佳添加量为2-3(g/100 kg牛奶).     

Natural skin coating of the apple and its influence on scald in storage III.—α-farnesene

In a study of apple fruits grown under English conditions it was found that at the time of the respiratory climacteric the concentration of α-farnesene in the waxy skin coating began to increase rapidly from a low level and at 12° reached a peak after about 30 days. in the relative amounts of farnesene produced there was little to distinguish the scald-resistant from the scald-sensitive apple variety. Under the various conditions of low-temperature storage in use, it was found that the farnesene content of the skin was most influenced by the nature of the atmosphere, whether air or 8% CO₂, white the farnesene content of the waxy skin coating was more responsive to delay at room temperature before storage, diphenylamine treatment or wrapping in oiled wraps. The results are discussed in relation to the theory that farnesene is a chemical factor in the induction of superficial scald.     

The influence of dietary fibre sources on growth,feed efficiency and digestibilities of dry matter and protein in rats

Hulls from Tower canola (TCH), Regent canola (RCH) and soya beans (SBH) were included at 10 or 20% in soya bean meal based diets for rats, to compare the effects of these fibre sources on growth, feed consumption, feed efficiency and dry matter and protein digestibilities. A soya bean meal based control diet and another diet containing a purified fibre source (Alphafloc) at a 10% level, were included for a further comparison. Each of the diets was fed to six rats in a 4-week feeding trial. The diets gave similar weight gain, feed consumption and feed efficiency values. The control diet had the highest mean coefficient of dry matter digestibility (80.8%) and the 20% SBH and Alphafloc diets had the lowest (72.4 and 72.2%). The canola hull and 10% SBH and Alphafloc diets had intermediate values (73.2–75.0%). There was a highly significant negative correlation between the dietary fibre content and the dry matter digestibility of the diets. The control and Alphafloc diets showed the highest and similar apparent (81.4 and 79.9%) and true (86.8 and 85.3%) digestibility values for dietary protein. The 20% canola and soya bean hull diets showed the lowest apparent (71.4–73.7%) and true (76.9–79.4%) digestibility coefficients. The 10% canola and soya bean hull diets had intermediate apparent and true protein digestibility values (73.2-75.3 and 78.4–80.6%, respectively). The chemical analysis of the fibre sources showed that Alphafloc had the highest cellulose content (88%) and the lowest lignin content (0.6%), while canola hulls had the lowest cellulose content (25.4–28.4%) and the highest lignin content (26.6–28.9%). Soya bean hulls had intermediate cellulose (50%) and low lignin (1.3%) contents. The results suggest that cellulose did not have a detrimental effect on the dietary protein digestibility but lignin and/or some other undetermined factors in the hulls had an adverse effect on protein digestibility.     

Turbidimetric studies on sinapic acid — rapeseed protein interaction

The interaction of sinapic acid (SA) with the two main protein fractions from rapeseed, the 11 S globulin and the 2 S protein fraction (napin), was studied by means of turbimetry. The turbidity maximum (solubility minimum) of the 11 S globulin was shifted from pH 6.3 to pH 5.4–5.7 by an excess of SA (mass ratio 1:1). Titration of the 11 S globulin with SA at constant pH (4.0, 4.5, 5.0) pointed to an excess binding of SA to the protein without a clear stoichiometric ratio. Napin did not show a significant turbidimetric effect by SA at room temperature. The presence of SA changed, however, the heat induced aggregation of napin. The decrease of turbidity pointed to a drop of the size of aggregated particles by SA. These findings are discussed as the results of combined non-covalent actions of SA to the proteins. Electrostatic interactions must play a certain role but not the dominant one.     

The influence of dietary inulin and oligofructose on the cell-mediated and humoral immunity in rats

This paper reviews evidence for the immune-enhancing effects of prebiotics. The influence of inulin and oligofructose on the immune functions and the structure of immune peripheral organs in male Wistar rats was investigated after 4 months feeding. Rats fed isocaloric purified diets contained 10% inulin or oligofructose. The rats of control group had no feeding any prebiotics. The enlargement of a number of T-cells and increasing of major histocompatibility complex (MHC-II) molecule on the surface of an antigen-presenting cells of spleen, mesenteric lymph nodes, thymus was noted. The increasing of content interleukin-2 and interleukin-4 in blood was noted in rats fed inulin and oligofructose. The increased activity of peritoneal macrophages was confirmed by enhance superoxid anion production and phagocytosis. The dietary prebiotics do not influence on the apoptosis of immunocytes. The immune-enhancing effects of prebiotics was confirmed by morphological investigation of peripheral lymphoid organs.     

Green tea and grape seed extracts — Potential applications in food safety and quality

Using “natural green” plant extracts or their derived products in various food and beverage applications is an increasing trend in the food industry. Selection of these plant extracts and their application depends on their functional properties, availability, cost effectiveness, consumer awareness and their effect on the sensory attributes of the final product. Green tea extract (GTE) and grape seed extract (GSE) are two popular plant extracts that have been widely used in various food and beverage applications. Green tea is a widely consumed beverage that has attracted more attention in the recent years due to its health benefits like antioxidant, antimicrobial, anticarcinogenic and anti-inflammatory properties. Grape seed extract is derived from the grape seeds that is extracted, dried and purified to produce polyphenolic compounds-rich extract that also has well documented antioxidant, antimicrobial and anti-inflammatory properties. These two plant extracts (polyphenolic and proanthocyanidin rich compounds) have potential antioxidant properties by inhibiting the lipid oxidation and warmed over flavors and antimicrobial activities against major food borne pathogens like Listeria monocytogenes, Salmonella Typhimurium, Escherichia coli O157:H7, and Campylobacter jejuni in preventing pathogen contamination. Furthermore, they have demonstrated synergism in antimicrobial activity when used in combination with organic acids (malic, tartaric acid, benzoic acids etc.), bacteriocins like nisin or chelating agents like EDTA in various model systems including fresh produce (fruits and vegetables), raw and ready-to-eat meat and poultry products. Apart from beneficial effects of grape seed extract in food safety and quality, concerns regarding the side effects of GSE are also addressed. Nevertheless, persistent recalls of the food products involving foodborne pathogens despite various control measures calls for efficient bacteriostatic and bactericidal agents and technologies to deliver the active components for an effective inhibition of pathogens. Therefore, further research involving electrostatic spray and nanoscale delivery of the active components present in these natural, green, plant extracts and using them as a component in multiple hurdle approach would enhance the food safety and quality in addition to providing alternative “green” solutions to the food processors.     

Available lysine. I.—Determination of non-N-terminal lysine in protein

An improved quantitative method for estimating ?-DNP-lysine is described. This method is applied to the determination of ?-DNP-lysine produced by the hydrolysis of dinitrophenylated proteins. The effect of the conditions of hydrolysis and of traces of chromic acid present during hydrolysis is presented. The use of dinitrophenylation as a method of determining non-N-terminal lysine was tested on three purified proteins and the results are discussed.     

Corn grist adjunct – application and influence on the brewing process and beer quality

In the brewing industry, barley malt is often partially replaced with adjuncts (unmalted barley, wheat, rice, sorghum and corn in different forms). It is crucial, however, to preserve constant quality in the beer to meet the expectations of consumers. In this work, how the addition of corn grist (10 and 20%) influences the quality of wort and beer was examined. The following parameters were analysed: wort colour, dimethyl sulphide (DMS) and protein content, non‐fermentable extract, extract drop during fermentation, alcohol content and the attenuation level of the beer, together with filtration performance. The samples (all‐malt, and adjunct at 10 and 20% corn grist) were industrial worts and the beers produced in a commercial brewery (3000 hL fermentation tanks). The application of 10 and 20% corn grist had an effect on the wort colour, making it slightly lighter (11.1 and 10.5°EBC, respectively) than the reference barley malt wort (12.2°EBC). The free amino nitrogen level, DMS and non‐fermentable extract were significantly lower in the worts produced with the adjunct; the alcohol content and attenuation levels were higher in the beers produced with adjunct. The use of corn grist, at the level of up to 20% of total load, appears to affect some of the technological aspects of wort and beer production, but it does not significantly influence the final product characteristics. Copyright © 2014 The Institute of Brewing & Distilling     

The influence of the dietary polyunsaturated fatty acids on the phagocyte's functional activity in rats

The influence of dietary polyunsaturated fatty acids on the superoxid anion production by peritoneal macrophages and phagocytosis by blood neutrophiles in male Wistar rats weighting 127.0 +/- 3.2 r was investigated after 3 months feeding. Rats fed isocaloric purified diets contained 24% fat representing combinations of lard, sunflower oil and fish oil (eiconol) providing the ratios of w6/w3 fatty acids equal 49.0; 6.1; 1.1. The increasing of superoxide formed by peritoneal macrophages and phagocytic activity of neutrophiles in the group received diet with the minimal ratios of w6/w3 fatty acids compared to that in rats fed diet with ratio 49.0 was noted. The increased activity of mononuclear-phagocytic system was confirmed by morphological investigation of peripheral lymphoid organs.     

Protein digestibility in dog. Effect of the quantity and quality of dietary fat (virgin olive oil and sunflower oil)

Protein digestibility has been estimated in dog when fed on two similar diets except their lipid quality (virgin olive oil and sunflower oil) from weaning up to 6 months of life. Experiments were carried out at 60, 105 and 150 days of adaptation to either diet. In dog, age does not seem to affect the protein digestive and metabolic utilization when fed on a high lipid content diet. A higher dietary fat percentage led to an increase of the mentioned parameters which could be caused to a delayed gastric emptying due to fat. As far as the fat quality is concerned, an improved protein digestive and metabolic utilization was evidenced in adult animals fed on olive oil. On the other hand, the weight progress was normal in both experimental groups. These results suggest that olive oil may have beneficial effects on protein digestibility as compared to sunflower oil.     

The analysis of dietary fibre—the choices for the analyst

The analysis of dietary fibre (which is defined as the sum of lignin and the polysaccharides not digested by the endogenous secretions of the human digestive tract) presents several problems to the analyst. Dietary fibre is a mixture of substances derived from the structural materials of the plant cell wall and a range of polysaccharides of a non-structural nature either present naturally in foods or derived from food additives. The complete analysis of such a complex mixture would be difficult and time consuming and a number of practical alternatives have been used. These include methods based on the enzymatic removal of protein and starch to give an ?indigestible residue’? and procedures based on extraction with neutral detergent solutions. These procedures in their present form do not measure water-soluble components and therefore underestimate dietary fibre. More detailed methods in which the water-soluble and water-insoluble non-cellulosic polysaccharides, cellulose and lignin were measured separately are described. In these the non-cellulosic fraction was characterised in terms of its component sugars. It is suggested that methods of this type are necessary to characterise dietary fibre analytically in order to account for the properties of dietary fibre.     

Genotype and growing season influence blueberry antioxidant capacity and other quality attributes

Forty‐two blueberry cultivars (thirty‐six Vaccinium ashei, three V. ashei derivative hybrids and three northern highbush standards) were evaluated for their antioxidant capacities and other fruit quality attributes over two growing seasons. Total anthocyanins, phenolic content and antioxidant capacities varied substantially among species and cultivars. ‘Early May’ (V. ashei) had the highest amounts of anthocyanins, phenolics and antioxidant capacity. Cultivars from V. ashei hybrid derivatives had lower mean antioxidant components than those from northern highbush standards or V. ashei. The antioxidant capacity, as well as total anthocyanins and phenolics, had significant cultivar × year interactions. Correlation coefficient between years for total anthocyanins, total phenolics and oxygen radical absorbance capacity were high with values of 0.86, 0.81 and 0.93, respectively. Similar interactions were observed for soluble solids content (SSC), sugar, titratable acid and organic acids among cultivars both within and across the growing seasons. Correlation coefficients between years for SSC, fructose, glucose and sucrose were 0.78, 0.71, 0.83 and 0.96, respectively. Fructose and glucose were detected as two major sugars with sucrose as a minor constituent. ‘Clara’ contained the highest amounts of SSC and sugars, while ‘Satilla’ had the lowest. In general, V. ashei cultivars had a higher mean SSC and sugar contents than did the hybrid derivatives or the northern highbush standards. Cultivars of V. ashei contained higher malic acid than citric acid, whereas in hybrid derivatives and northern highbush cultivars, citric acid was the predominant organic acid. The diversity in the amount of these fruit quality attributes and antioxidant capacities presents a great opportunity for genetic improvement of blueberries through breeding programmes. The objective of the study was to identify blueberry cultivars with high antioxidant activity and good fruit quality, so they can be used as parents for future blueberry breeding programmes to develop new cultivars with higher antioxidant activity.     

不同种类蛋白质与大鼠锌代谢关系的研究

通过给予SD种Ⅱ级成年雄性大鼠 4种不同蛋白质的合成饲料 ,研究不同种类蛋白质对锌代谢的影响。大鼠随机分成谷类蛋白质组 (Ⅰ )、大豆蛋白质组 (Ⅱ )、酪蛋白质组 (Ⅲ )、谷豆混合蛋白质组 (Ⅳ )四组 ,每组 11只 ,自由摄食饮水。实验结果显示 ,锌摄入量 :Ⅳ组 >Ⅱ组 >Ⅲ组 >Ⅰ组 ,但各组间差别无显著性 ;粪锌含量 :Ⅰ组 >Ⅲ组 >Ⅱ组 >Ⅳ组 ,其中Ⅳ组与Ⅰ组差别有显著性 (P <0 0 5 ) ;尿锌含量 :Ⅰ组 >Ⅱ组 >Ⅳ组 >Ⅲ组 ,但各组间差别无显著性 ;表观锌吸收率 :Ⅳ组 >Ⅱ组 >Ⅲ组 >Ⅰ组 ,其中Ⅳ组与Ⅰ组差别有显著性 (P <0 0 5 ) ;表观锌潴留率 :Ⅳ组 >Ⅱ组 >Ⅲ组 >Ⅰ组 ,Ⅰ组与Ⅱ组、Ⅲ组、Ⅳ组组间皆差别有显著性 (P <0 0 5 )。谷类蛋白质与大豆蛋白质混合后 ,其生物利用率提高 ,能较明显地增加锌的吸收率与潴留率。提示大豆蛋白质尤其谷豆蛋白质是一种改善锌缺乏的优质食品。     

Responses of lactating cows to dietary sodium source and quantity and potassium quantity during heat stress

Effects of heat stress and added dietary sodium bicarbonate (0 or 1.0% of dry matter), sodium chloride (0 or .73% of dry matter), and total dietary potassium (1.3 or 1.8% of dry matter) on acid-base status, production, and mineral metabolism of lactating Holstein cows were evaluated. Design was split-plot with 24 cows in shade or no shade environments; dietary treatments were arranged as a 2 X 2 X 2 factorial within each environment. Basal diet (38% corn silage:62% concentrate) contained .18% sodium; sodium bicarbonate and sodium chloride treatments were in addition. All dietary treatments were equal in chloride content. Cows in no shade exhibited signs of respiratory alkalosis during the hot part of the day. Daily feed intake was lower in no shade than shade but milk yield and percent milk fat were not affected by environment. Sodium bicarbonate addition increased actual and 4% fat-corrected milk yields and percent milk fat. Sodium chloride addition increased actual and 4% fat-corrected milk yield when adjusted for amount of feed intake, and 1.8% dietary potassium increased feed intake and actual milk yield. Increasing total dietary sodium from .18 to .55%, from either supplemental source, enhanced 4% fat-corrected milk production, but combination of sources (.88% total sodium) showed no additional benefit over .55%.     

Dietary protein deficiency and the influence of chlorfenvinphos on the biological parameters in rats

Male and female rats of Wistar strain were fed from the 6th week of life on during 10 and 30 days the diet containing 4.5% or 26% protein without or with addition of chlorfenvinphos (Chl) in concentrations of 5, 100 and 1000 ppm. The following was stated:

• In the case of optimal-protein diet (26% protein): the inhibitory effect of Chl on the body weight gain at its highest concentration; the increased relative weight of liver, ovaries and adrenals dependent on the amount of the insecticide in the diet.
• In the case of low-protein diet (4.5% protein): the reduced rate of the body weight gain already at 5 ppm, pronounced at 100 ppm and strongly marked at 1000 ppm of Chl; increase of the relative weight of testicles, adrenals and decrease of the relative weight of the spleen connected with the increasing concentrations of Chl.
• In rats with the most decreased rate of the body weight gain (in case of Chl) an increase of the relative weight of the brain.
• Congestion of the heart, spleen and kidneys after 30 days on diets containing 100 and 1000 ppm of Chl, independent of the amount of protein in the diet.
• Eosinophilic infiltrations in the lungs of rats obtaining the 100 ppm-contaminated low-protein diet during 30 days.
• Focal degenerative changes in the cells of the exocrine pancreas and proliferation of lymphatic nodules in the spleen mainly in rats receiving the 1000 ppm-contaminated optimal-protein diet for 30 days.
• After withdrawal of Chl from the diets changes caused by this insecticide showed reversal trends.

     

Effect of the quality of dietary protein on the degree of its metabolization in the body

The authors studied the effect of postponed enrichment of low-grade protein (gluten) by the limiting amino acids (lysine and threonine) on the intensity of the cellular protein synthesis and on the PER. It was established that the rate of incorporation of the labeled amino acid 14C-leucine into cellular proteins changes parallel with change in the PER. Low-grade protein nutrition has an adverse effect on the metabolism. If the diet containing low-grade protein is supplemented with amino acids, the intensity of metabolic processes rises almost to the level seen during adequate animal protein nutrition. A direct and statistically significant correlation was found between the biological value of the protein consumed and the intensity of protein biosynthesis in the cells. It is concluded that measurement of the intensity of the cellular protein synthesis in a good biological test for determination of the test protein quality.     

管理——织造质量与产量的保证

在大批量生产中,为了加工高档的机织产品且在订单报价上保持竞争优势,工厂必须首先具有可控制的计划和管理,需全面了解从纤维到织物的整个生产流程,以保证织物生产获得更多的利润.