Preservation of vitamins during preparation of dry specialized dairy products

Preservation of vitamins A, E, C, B6, B1, B2, B5, Bc was studied during preparation of dried special-purpose milk mixtures ("Solnyshko", "Inpitan", enpits, low-lactose mixtures) and after storage ("Inpitan", and low-lactose mixtures) during 1 year at 4 and 18 degrees C. It has been established that vitamins A, E and C are most subjected to deterioration during production of dried special-purpose mixtures, their losses comprise 17-47, 18-43, 13-41%, respectively. B2 and B5 were most resistant in the process of the mixture production. No significant losses of vitamins were recorded during storage of "Inpitan" and low-lactose mixtures.     

Nutritive value of a new protein product--dry protein mixture

A dry protein mixture (DPM) consists of dry slaughtered animal blood clarified by means of the peroxide-catalase system and dry skim milk at a ratio of 1:1. A study was made of organoleptic properties of the DPM, the composition of nutrients and biological efficacy in experiments on animals. The DPM is light yellow powder without specific taste and odor of blood, contains 58.4% of protein, 1.36% of fat, 26.71% of carbohydrates (lactose), and 8.19% of mineral substances. DPM proteins contain all the essential amino acids. As regards their biological efficacy they are not inferior to that of casein. The DPM is rich in calcium (606 mg/100 ml), phosphorus (645 mg/100 ml) and particularly in iron (106 mg/100 ml). Digestibility of iron examined on rats appeared to be high (31.2%). The new product is recommended for rational and dietetic nutrition.     

Lethality of chlorine, chlorine dioxide, and a commercial fruit and vegetable sanitizer to vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis

Chlorine, ClO2, and a commercial raw fruit and vegetable sanitizer were evaluated for their effectiveness in killing vegetative cells and spores of Bacillus cereus and spores of Bacillus thuringiensis. The ultimate goal was to use one or both species as a potential surrogate(s) for Bacillus anthracis in studies that focus on determining the efficacy of sanitizers in killing the pathogen on food contact surfaces and foods. Treatment with alkaline (pH 10.5 to 11.0) ClO2 (200 microg/ml) produced by electrochemical technologies reduced populations of a five-strain mixture of vegetative cells and a five-strain mixture of spores of B. cereus by more than 5.4 and more than 6.4 log CFU/ml respectively, within 5 min. This finding compares with respective reductions of 4.5 and 1.8 log CFU/ml resulting from treatment with 200 microg/ml of chlorine. Treatment with a 1.5% acidified (pH 3.0) solution of Fit powder product was less effective, causing 2.5- and 0.4-log CFU/ml reductions in the number of B. cereus cells and spores, respectively. Treatment with alkaline ClO2 (85 microg/ml), acidified (pH 3.4) ClO2 (85 microg/ml), and a mixture of ClO2 (85 microg/ml) and Fit powder product (0.5%) (pH 3.5) caused reductions in vegetative cell/spore populations of more than 5.3/5.6, 5.3/5.7, and 5.3/6.0 log CFU/ml, respectively. Treatment of B. cereus and B. thuringiensis spores in a medium (3.4 mg/ml of organic and inorganic solids) in which cells had grown and produced spores with an equal volume of alkaline (pH 12.1) ClO2 (400 microg/ml) for 30 min reduced populations by 4.6 and 5.2 log CFU/ml, respectively, indicating high lethality in the presence of materials other than spores that would potentially react with and neutralize the sporicidal activity of ClO2.     

Characteristics of the nutrition and blood lipids of the native residents of Chukot Peninsula and the Buryat ASSR

Simultaneous epidemiologic investigations of representative samplings of the male population, aged from 30 to 59 years, were carried out in Chukot Peninsula and the Buryat ASSR in 1981-1982 and 1985-1986 years. The programme of the study included standard questioning to reveal angina of effort according to the WHO Cardiologic Questionnaire, ECG recording at rest, arterial pressure measuring (twice), anthropometry, biochemical blood assay (the content of total cholesterol, triglycerides and high density lipoprotein cholesterol). Actual nutrition was studied by the method of "daily reproduction" in 104 residents of Markovskaya tundra (85.3%), in 165 residents of Chukot Peninsula (73.4%) and in 476 residents of the Buryat ASSR (95.2% of the planned number). Differences have been revealed in the characteristics of nutrition and blood lipid content between the native residents of Chukot Peninsula and the Buryat ASSR. Certain relationship has been determined between dyslipoproteinemia incidence and differences in the nutrition of the compared population groups.     

芝麻油中芝麻素、芝麻林素的研究

本文利用高效液相色谱测定不同芝麻样本提取油以及市购芝麻油中芝麻素、芝麻林素的含量。色谱柱为HibarRT250-4(C18,250mm×4.6mm,填充粒度5μm);流动相:甲醇:水=75:25(V/V);流速:1ml/min;检测波长:280nm。测定结果表明:被测两峰完全分离,且峰形较好,线性范围10～100μg/ml,芝麻素、芝麻林素平均回收率分别为101.1%、100.2%重现性(n=5)分别为芝麻素RSD=2.31%、芝麻林素的RSD=3.05%,最低检出限:芝麻素为1.5μg/ml,芝麻林素为2.5μg/ml(以进量浓度计)。油样中芝麻素的含量范围为0.35%～0.72%、芝麻林素的含量范围为0.32%～0.48%,制油工艺中焙炒工序强度对芝麻林素含量变化具有一定影响。     

Lesinurad原料药中7种有机溶剂残留的测定

目的建立同时测定Lesinurad原料药中丙酮、二氯甲烷、正己烷、乙酸乙酯、四氢呋喃、甲苯、N,N-二甲基甲酰胺(DMF)残留量的方法。方法采用气相色谱法(GC)。色谱柱为RESTEK Rtx-502.2毛细管柱,程序升温,柱温为40℃,维持2 min,以每分钟5℃的速率升温至200℃。进样口温度为180℃,检测器为氢火焰离子化检测器,检测温度为220℃,载气为氮气,流速为2.0 ml/min,分流比为20:1,直接进样,进样量为1μl。按外标法进行定量分析。结果7种残留溶剂峰分别与相邻峰分离完全。丙酮、二氯甲烷、正己烷、乙酸乙酯、四氢呋喃、甲苯和DMF的线性范围分别为100~600μg/ml(r=0.9998),12~72μg/ml(r=0.9993),5.8~34.8μg/ml(r=0.9990),100~600μg/ml(r=0.9996),14.4~86.4μg/ml(r=0.9995),6~36μg/ml(r=0.9991),17.6~105.6μg/ml(r=0.9989);定量限分别为4.8,6.1,2.9,5.0,3.6,3.0,3.9μg/ml,检测限分别为1.6,2.0,1.0,1.8,1.2,1.0,1.3μg/ml;加样回收率分别为98.63%~99.89%(RSD=0.61%,n=9),98.59%~99.94%(RSD=0.78%,n=9),97.46%~99.23%(RSD=0.76%,n=9),98.20%~99.66%(RSD=0.78%,n=9),98.34%~99.56%(RSD=0.86%,n=9),97.46%~99.96%(RSD=0.65%,n=9),97.56%~100.63%(RSD=0.82%,n=9)。结论该方法简单、准确、重复性好,可用于Lesinurad原料药中7种残留溶剂的检测。     

谷氨酸脱羧酶活力测定中GABA比色定量方法研究

建立了谷氨酸脱羧酶活力测定中γ-氨基丁酸比色测定方法,该方法灵敏度高、精确性和重现性好。测定程序为:取酶反应液0.4ml,加入Na2CO3(1mol/L)0.1ml、pH10.0硼酸盐缓冲液(0.2mol/L)0.5ml、6%苯酚1ml,混匀,于室温下(20℃)在5min内加入5.2%NaClO溶液1ml,混匀后放置4～8min,然后沸水浴l0min,立即冰浴20min,待溶液出现蓝绿色后,加入2.0ml60%乙醇溶液,混匀后于20℃水浴中放置20～40min,测定640nm处的吸收值。经采用比色法和高效液相色谱法对谷氨酸脱羧酶酶反应液进行测定,两种方法的测定结果相对误差为4.91%。     

羊乳中替米考星残留的检测方法研究

建立了羊乳中替米考星残留的反相高效液相色谱检测方法。羊乳按1:1(V/V)用乙腈提取,上清液以5ml/min 流速过C18 SPE 柱,采用乙腈- 水(20:80,V/V)洗涤、乙腈- 水(90:10,V/V)洗脱,并以0.1mol/L 乙酸铵- 乙腈-甲酸(60:30:10,V/V)为流动相,采用高效液相色谱仪在280nm 处使用紫外检测器检测。本法定量限(LOQ)为0.02μg/ml,平均回收率范围在90.3%～98.1% 之间,线性范围为0.01～25μg/ml,变异系数范围在4.1%～8.9% 之间。本法可满足残留分析的要求,为羊乳中替米考星的残留分析提供了可靠的检测方法。     

Determination of the extracellular lipases of Pseudomonas fluorescens spp. in skim milk with the beta-naphthyl caprylate assay

A method based on the hydrolysis of beta-naphthyl caprylate (beta-NC) has been developed for quantitating extracellular lipase from Pseudomonas fluorescens. The assay was extremely sensitive to skim milk (SM); as little as 0.02 ml raw SM in a 2.0 ml reaction mixture resulted in an apparent loss of 50% of the lipase activity. Activity improved 3-fold when trypsin (50 micrograms/ml) was included in the reaction mixture. When super-simplex optimization was used to determine the optimum levels of beta-NC, Na taurocholate (NaTC), SM/lipase mixture and trypsin for maximum activity, NaTC was found to be unnecessary for activity. Subsequent addition of 15 mM-NaTC resulted in 80% loss of activity. On the other hand, NaTC was required for native lipase activity in the presence of SM. Native lipase was completely inhibited by heating at 70 degrees C for 2 min, while B52 lipase retained 75% of its activity under the same conditions. The assay was able to detect lipase produced by Ps. fluorescens B52 in SM at 5 degrees C when the cell density exceeded 10(8) colony forming units/ml. The presence of butterfat (3.5%) in the SM assay inhibited B52 lipase by 97%. The beta-NC assay gave results comparable to the tributyrin agar diffusion assay using cell-free extracts of ten strains of common dairy psychrotrophs. The results suggest that the beta-NC assay may be useful for determining lipase activity in raw SM.     

多源复合天然保鲜剂对冷却猪肉的保鲜效果

为寻求安全、有效的纯天然复合保鲜液,保证冷却猪肉货架期的品质,将6%(质量分数)的丁香与桂皮提取液各12.5mL与壳聚糖5g、蜂胶1g、Nisin 0.75g、溶菌酶0.75g、茶多酚5g混合,配制成2%复合天然保鲜剂,浸泡冷却猪肉,真空包装,(4±1)℃低温冷藏。通过测定冷却猪肉在冷藏过程中的微生物指标、理化指标和肉色指标,考察复合保鲜剂对冷却猪肉的保鲜效果。试验同时设阳性对照(2%乳酸处理组)和阴性对照(无菌蒸馏水处理组)。试验结果表明,在同一贮藏期内2%复合天然保鲜剂和2%乳酸处理组的各项指标均优于无菌蒸馏水处理组,且以2%复合天然保鲜剂对冷却猪肉的保鲜效果最好;贮存3周时,2%保鲜剂处理组细菌总数的对数值[lg(cfu/mL)]6.58,pH6.5,TRA值0.30,TVB-N值16mg/100g,TBARS值0.05mg/100g,MMb含量60%和汁液流失率0.06%,肉色暗红,风味较好,达到保鲜目标要求。     

Colorimetric determination of sulfite in "kanpyo" (dried gourd shavings) and "konnyakuseiko" (devil's-tongue fine powder) using sulfite oxidase and catalase

A simple and convenient method for colorimetric determination of sulfite in foods based on its conversion to formaldehyde with sulfite oxidase and catalase was developed. Sulfite in a sample was extracted with water and then diluted with methanol. One mL of sample solution containing about 5-10 micrograms of sulfite was taken into a test tube with a ground-glass stopper, and 3 mL of 0.04 mol/L borate buffer (pH 8.7), 1 mL of 0.4% 3-methyl-2-benzothiazolinone hydrazone (MBTH) solution, 2,000 units of catalase solution and 1.0 units of sulfite oxidase were added. The mixture was incubated for 35 minutes at 37 degrees C. Then 0.15 mL of 1 mol/L hydrochloric acid and 5 mL of 0.2% iron(III) nitrate solution were added. The reaction mixture was transferred to a measuring flask after standing for 5 minutes at room temperature, and diluted to 20 mL with methanol. The absorbance of this solution was measured using a spectrophotometer at the wavelength of 635 nm. The calibration curve prepared with sodium sulfite showed linearity between 0 to 16 micrograms/mL as sulfur dioxide. The recoveries of sulfite in "Kanpyo" (dried gourd shavings) and "Konnyaku-seiko" (devil's-tongue fine powder) by the proposed method were 97-104%, and the coefficients of variation were below 6%. The sulfite values in these foods determined by the proposed method were reasonably consistent with those obtained by the bubbling distillation-alkaline titration method.     

玉米短肽的制备及其抗氧化活性的研究

酶解玉米蛋白对生产高营养且易于吸收、高附加值的具有生物学功能特性的生物产品具有重要意义。本文通过Alcalase AF2．4L和风味蛋白酶在适当条件下酶解玉米蛋白，酶解2h，水解度可达31％，短肽得率超过70％以上。经Sephadext^TMG-25进行分离，对其分离后的各组分进行抗氧化活性的研究，经测定，玉米短肽在浓度为1mg／ml时对邻苯三酚（PR）的自氧化抑制率达43．9％，相当于5U／ml SOD的抗氧化活性。     

Chemical composition, in vitro cytotoxic and antioxidant activities of the essential oil and major constituents of Cymbopogon jawarancusa (Kashmir)

The chemical composition of the hydrodistillate of aerial parts of Cymbopogon jawarancusa, a natural grass considered as major forage for animal nutrition, used in food because of the presence of sufficient concentration of minerals like calcium and potassium was analysed by capillary GC–FID, GC–MS and ¹³C NMR. Seventeen constituents representing 97.8% of the total oil with piperitone (58.6%) and elemol (18.6%) as major constituents were identified. In vitro cytotoxicity of the oil and its constituents on human cancer cell lines THP-1 (leukemia), A-549 (lung), HEP-2 (liver) and IGR-OV-1 (ovary) was evaluated by Sulphorhodamine-B assay. The oil was found to be more potent than its components against cancer cell lines tested with IC₅₀ of 6.5 μg/ml (THP-1), 6.3 μg/ml (A-549), 7.2 μg/ml (HEP-2) and 34.4 μg/ml (IGR-OV-1). Antioxidant activity of oil and its constituents was evaluated by DPPH assay. In conclusion, the results demonstrate potent cytotoxic and antioxidant effects of oil, and its components like piperitone, α-pinene, β-caryophyllene and β-elemene.     

Comparison of effects of Wasabia japonica and allyl isothiocyanate on the growth of four strains of Vibrio parahaemolyticus in lean and fatty tuna meat suspensions.

Lean tuna meat suspensions (LEAN), with a fat content of 0.006%, and fatty tuna meat suspension (FATTY), with a fat content of 3.0% were inoculated with four strains of Vibrio parahaemolyticus and wasabi (Wasabia japonica Matsumura) or allyl isothiocyanate (AIT) was added before incubation at 37 degrees C. During the incubation, viable Vibrio counts were determined on TCBS agar plates. Both LEAN and FATTY suspensions were inoculated with V. parahaemolyticus AOTO-81, (1.28+/-0.20) x 10(2) CFU/ml, followed by addition of 20 mg wasabi/ml, and incubation for 8 h. The viable Vibrio counts were (7.76+/-5.93) x 10(5) CFU/ml in LEAN and (3.50+/-2.65) x 10(1) CFU/ml in FATTY. When the same strain, at (1.18+/-0.22) x 10(2) CFU/ml, was incubated for 8 h with 50.9 microg AIT/ml, viable Vibrio counts were (4.79+/-1.78) x 10(4) CFU/ml in LEAN and (1.80+/-1.30) x 10(1) CFU/ml in FATTY. Growth of the other three strains with wasabi or AIT was shown to be less in FATTY than in LEAN. These results indicate that growth of V. parahaemolyticus is inhibited more in FATTY than in LEAN by wasabi and allyl isothiocyanate.     

2013年唐山市超市预包装食品营养标签标示现况调查

了解2013年1月1日正式实施GB 28050—2011《食品安全国家标准预包装食品营养标签通则》(以下简称《通则》)后,唐山市超市预包装食品营养标签标示现况。方法 参考《通则》设计调查表,对唐山市某大型超市正在出售的全部七大类预包装食品营养标签标示内容进行调查,并按《通则》要求进行分析。结果 2013年调查国产预包装食品885种。营养标签总标示数为734种(82.9%)。各类食品中标示数(率)排在前三位的分别为饮料类50种(100%)、乳及乳制品80种(98.9%)、肉类制品98种(90.7%)。排在最后一位的是调料类123种(65.4%)。营养成分表中能量和核心营养素均标示的为718种(97.8%),其中形式全部规范的有696种(96.9%)。有营养标签的食品中,标示营养声称的食品数为78种(10.6%);其中标示规范的食品数为76种(97.4%),有营养成分功能声称的食品数为55种(7.5%),其中标示规范的食品数为53种(96.4%)。结论 目前《通则》在实践中得到了有效推广,各类食品营养标签中要求强制标示的内容标示率和规范率除调料类食品外均达到80%以上。     

麦芽糖月桂酸酯的分离纯化与结构鉴定

采用薄层层析(TLC)和硅胶柱层析分离纯化了脂肪酶催化合成的麦芽糖月桂酸酯,然后用高效液相色谱(HPLC)、质谱(MS)、红外光谱(IR)和核磁共振(NMR)法鉴定了纯化组分的分子结构。TLC分离麦芽糖月桂酸酯的合理条件:点样量5μl,以氯仿/甲醇(4:1,V/V)展开15min,然后用5%硫酸乙醇溶液喷雾、120℃显色20min。硅胶柱层析分离麦芽糖月桂酸酯的适宜条件:10ml反应液上12mm×1000mm硅胶(100～200目)层析柱,流动相为氯仿/甲醇(4:1,V/V),流速18ml/h,按1管/10min收集洗出液。两种分离组分分别为6’-O-麦芽糖月桂酸酯和6,6’-O-麦芽糖月桂酸二酯。     

The effects of a mixture of oxygen, carbon dioxide and nitrogen in the ratio 1:1:8 on the longevity and the rate of increase of populations of Sitophilus zeamais Mots

After the continuous exposure of adult Sitophilus zeamais Mots. to a mixture of oxygen, carbon dioxide and nitrogen (1:1:8), the mean longevities of males were reduced from 56 days in air to 49 days in the gas mixture and of females from 75-63 days. The number of offspring was about 40% of that obtained when adults were kept in air. The finite rate of natural increase and its natural logarithm, the infinite rate of increase, have been determined for populations kept in air (r = 0.32), in the gas mixture during oviposition (r = 0.22), in the gas mixture during development (r = 0.20) and in the gas mixture throughout (r = 0.12).     

Enzymatic oxydation of linoleic acid: Formation of bittertasting fatty acids

Summary Linoleic acid was oxidized with a protein fraction from soya beans (25°C; 2 h), in which lipoxygenase and peroxydase activities occurred. The fatty acids formed were isolated and, after emulsification with a sugar ester, were evaluated for bitter taste. The main components of the bitter-tasting fraction was a mixture of 9.12.13-trihydroxyoctadec-10- and 9.10.13-trihydroxyoctadec-11-enoic acids. The taste threshold lies in the range 0.6–0.9 mol/ml. Two further trihydroxy-acids and two oxodihydroxy-acids were also identified in the bitter-tasting fraction.

---

Enzymatische Oxydation von Linolsäure: Bildung von Fettsäuren mit Bittergeschmack

Zusammenfassung Linolsäure wurde mit einer Proteinfraktion aus Sojabohnen oxydiert (25°C; 2 Std), in der Lipoxygenase- und Peroxydaseaktivitäten vorkamen. Die gebildeten Fettsäuren wurden isoliert und nach Emulgierung mit einem Zuckerester auf Bittergeschmack verkostet. Hauptkomponente der bitter schmeckenden Fraktion war ein Gemisch aus der 9,12,13-Trihydroxyoctadec-10- und der 9,10,13-Trihydroxyoctadec-11-ensäure. Die Geschmacksschwelle liegt im Bereich 0,6–0,9 mol/ml. Zwei weitere Trihydroxysäuren und zwei Ketodihydroxysäuren wurden außerdem in der bitter schmeckenden Fraktion identifiziert.

---

---

We are grateful to the Deutsche Forschungsgemeinschaft for supporting this work     

Inactivation of Escherichia coli O157: H7 and Listeria monocytogenes by PR-26, a synthetic antibacterial peptide.

This study reports the antibacterial effect of PR-26, a synthetic peptide derived from the first 26 amino acid sequence of PR-39, an antimicrobial peptide isolated from porcine neutrophils. A three-strain mixture of Escherichia coli O157:H7 or Listeria monocytogenes of approximately 10(8) CFU was inoculated to a final concentration of 10(7) CFU/ml in 1% peptone water (pH 7.0), containing 50 or 75 microg/ml of PR-26, and incubated at 37 degrees C for 0, 6, 12, and 24 h; at 24 degrees C for 0, 12, 24, and 36 h; or at 10 or 4 degrees C for 0, 24, 72, and 120 h. Control samples included 1% peptone water inoculated with each pathogen mixture but containing no PR-26. The surviving population of each pathogen at each sampling time was determined by plating on tryptic soy agar with incubation at 37 degrees C for 24 h. At 37 degrees C, PR-26 decreased E. coli O157:H7 and L. monocytogenes populations by >5.0 log CFU/ml at 12 h, with complete inactivation at 24 h. At 24 degrees C, PR-26 reduced E. coli O157:H7 and L. monocytogenes by approximately 3.5, 4.0, and 4.5 log CFU/ml at the end of 12-, 24-, and 36-h incubations, respectively. At 4 and 10 degrees C, the inhibitory effect of PR-26 on E. coli O157:H7 and L. monocytogenes was significantly lower (P < 0.05) than that at 37 and 24 degrees C: a 2- to 3-log CFU/ml reduction was observed at 120-h incubation. Results indicate that PR-26 could potentially be used as an antimicrobial agent, but applications in appropriate foods need to be validated.     

超高效液相色谱-波长切换法同时测定健脾丸(浓缩丸)中4种成分的含量

目的建立同时测定健脾丸(浓缩丸)中党参炔苷、白术内酯I、白术内酯II、白术内酯III 4种成分含量的方法。方法采用超高效液相色谱法(UPLC),色谱柱为Poroshell 120 SB-C18(4.6 mm×100 mm,2.7μm),流动相为乙腈-0.1%乙酸,梯度洗脱,流速为0.5 ml/min,检测波长为270 nm(党参炔苷和白术内酯III)和220 nm(白术内酯I和白术内酯II),柱温为30℃,进样量为5μl。结果党参炔苷、白术内酯I、白术内酯II、白术内酯III检测线性范围分别为10.157~203.14μg/ml(r=0.9998),1.641~32.82μg/ml(r=0.9997),1.066~21.32μg/ml(r=0.9999),1.859~37.18μg/ml(r=0.9999),平均回收率分别为96.91%(RSD=1.71%,n=6),96.56%(RSD=1.39%,n=6),93.93%(RSD=1.71%,n=6),96.00%(RSD=1.66%,n=6),精密度、稳定性、重复性试验的RSD<2.0%。结论该方法重复性好、结果准确,可用于健脾丸(浓缩丸)的质量控制。