黄原胶高产菌株HL-9901发酵培养基的优化

采用黄单胞杆菌（Xanthomonascampestris）诱变株HL－9901进行试验。采用正交设计与统计学分析,确定出最佳发酵培养基配方为：淀粉4％,葡萄糖2％,蛋白陈0．1％,NaNO31％,（NH4）2HPO40．3％,K2HPO40．3％,MgSO40．1％,CaCO30．09％。30h时补加1．5％的葡萄糖。最终产率可达到4．063g／100mL,碳源转化率为54．17％,发酵时间可缩短至54h。并测定了最优化培养基摇瓶发酵中相关控制参数的变化。     

Impact of guar and xanthan gums on proofing and calorimetric parameters of frozen bread dough

The influence of guar and xanthan gum and their combined use on dough proofing rate and its calorimetric properties was investigated. Fusion enthalpy, which is related to the amount of frozen water, was influenced by frozen dough formulation and storage time; specifically gum addition reduced the fusion enthalpy in comparison to control formulation, 76.9 J/g for formulation with both gums and 81.2 J/g for control, at 28th day. Other calorimetric parameters, such as T_g and freezable water amount, were also influenced by frozen storage time. For all formulations, proofing rate of dough after freezing, frozen storage time and thawing, decreased in comparison to non-frozen dough, indicating that the freezing process itself was more detrimental to the proofing rate than storage time. For all formulations, the mean value of proofing rate was 2.97 ± 0.24 cm³ min⁻¹ per 100 g of non-frozen dough and 2.22 ± 0.12 cm³ min⁻¹ per 100 g of frozen dough. Also the proofing rate of non-frozen dough with xanthan gum decreased significantly in relation to dough without gums and dough with only guar gum. Optical microscopy analyses showed that the gas cell production after frozen storage period was reduced, which is in agreement with the proofing rate results.     

鳙鱼鱼糜凝胶特性改良的研究

研究了不同质量分数的大豆分离蛋白(SPI)、魔芋胶(KG)对鳙鱼Aristichthy nobilis鱼糜凝胶特性的影响．结果表明,加入SPI或KG均可使鳙鱼鱼糜凝胶的硬度、弹性、凝胶强度及持水性明显增加,且浓度越大,其作用越强,但这2种物质会降低鱼糜凝胶的白度．SDS-聚丙烯酰胺凝胶电泳表明,SPI可增强肌球蛋白重链带(MHC)的强度,而KG对MHC带的强度影响不大．电镜分析则表明SPI和KG的加入都可使鳙鱼鱼糜形成致密、均匀的凝胶网络结构．     

Effects of enzymatic hydrolysate of locust bean gum on digestibility,intestinal morphology and microflora of broilers

To investigate the effects of different levels of enzymatic hydrolysate of dietary locust bean gum on nutrient digestibility, intestinal morphology and microflora of broilers, a total of 768 one-day-old Arbor Acres (AA) broiler chicks were randomly divided into 6 treatments with 8 replicates per treatment and 16 birds per replicate. The treatments were as follows: (1) CON, basal diet; (2) ANT, basal diet +62.5 mg/kg flavomycin; (3) LBG, basal diet +0.1% locust bean gum; (4) ELBG-0.1, basal diet +0.1% enzymatic hydrolysate of LBG; (5) ELBG-0.2, basal diet +0.2% enzymatic hydrolysate of LBG; and (6) ELBG-0.3, basal diet +0.3% enzymatic hydrolysate of LBG. The digestibilities of ether extract, crude protein and dry matter were increased (p < .01) in broilers fed the ELBG-0.3 diet compared with the CON and LBG diets on day 21. Duodenal villus height and the ratio of the villus height to crypt depth were greater (p < .01) in broilers fed the ELBG-0.3 diet than the CON, ANT and LBG diets. Jejunum villus height was higher (p < .05) in broilers fed the ELBG-0.2 and ELBG-0.3 diets than the CON diet. The number of caecal Escherichia coli was reduced (p = .01) in broilers fed the ELBG-0.2 and ELBG-0.3 diets compared with the CON diet. The number of caecal Lactobacilli was greater (p < .05) in broilers fed the ELBG-0.3 diet than the CON and ANT diets. In summary, the addition of 0.3% locust bean enzymatic hydrolysate can increase the surface area of intestinal villi and the number of beneficial bacteria, inhibit the proliferation of harmful bacteria, maintain the balance of intestinal microflora and improve the digestibility of nutrients.     

打磨法提取亚麻籽胶粉的工艺

为提高亚麻籽综合加工效益,解决现有亚麻籽胶生产存在问题,在对亚麻籽结构充分了解基础上,利用亚麻籽胶分布在亚麻籽外表面的结构特点,提出采用高速旋转砂辊对亚麻籽表面进行打磨提取亚麻籽胶粉的技术设想,并借助实验砂辊碾米机开展研究。结果表明：采用砂辊打磨亚麻籽在控制亚麻籽装填率在40%～80%时打磨均能够顺利获取亚麻籽胶粉,说明打磨提取亚麻籽胶粉技术可行;在装填率40%、打磨时间200 s脱脂胶粉得率最高达6.06%±0.51%;在装填率80%情况下,打磨设备提取的脱脂亚麻籽胶粉产量最高,打磨时间200 s,胶粉黏度测定值为(5 200±680) mPa.s,高于现有市售干法亚麻籽胶产品黏度而低于市售湿法亚麻籽胶产品黏度;通过对比检测打磨前后压榨亚麻籽油的色泽、气滋味、酸价和过氧化物指标,打磨提取亚麻籽胶粉过程对亚麻籽压榨油品质无明显影响。采用先打磨提取部分亚麻籽胶粉再进行压榨制油加工,将增加亚麻籽加工产品品种,提高加工效益。     

昆虫病原线虫Steinernema carpocapsae A11品系叶面应用辅助剂的筛选

研究了12种物质对昆虫病原线虫Steinernema carpocapsae A11品系的抗干燥保护作用。这些物质在试验浓度下对线虫和小菜蛾3龄幼虫的存活以及对线虫的侵染率都无显著影响。线虫加入抗干燥剂后经滤纸干燥法处理和叶面喷洒试验结果都表明,甘油和黄原胶的抗干燥保护作用最好。     

抹茶味面筋蛋白基口香糖的研制

以小麦面筋为胶基原料,以水、甘油、复合甜味剂(山梨醇和麦芽糖醇)以及抹茶4种辅料研制抹茶味面筋蛋白基口香糖。通过单因素试验确定水、甘油、复合甜味剂(山梨醇和麦芽糖醇)以及抹茶4种辅料的合适用量,再选取用水量、甘油用量、山梨醇和麦芽糖醇比例3个因素进行均匀试验以优化配方。通过感官评定确定抹茶味面筋蛋白基口香糖的最佳配方,并制作相关的产品,最后进行质构分析评判产品性能。感官评定结果表明,口香糖的最佳配方为:小麦面筋蛋白10 g,薄荷冰0.02 g,β-环糊精0.8 g,抹茶0.2 g,水11 g,甘油1.2 g,山梨醇和麦芽糖醇各为2.5 g。对口香糖的质构测定结果进行回归和相关性分析,表明测定结果能较好地预测口香糖的硬度、弹性、黏聚性和咀嚼性,但口香糖的硬度、弹性、黏聚性与辅料之间(除加水量与硬度、咀嚼性、黏聚性3个因素之间),相关性不显著。     

Electrokinetic properties of variable charge clays in the presence of an anionic xanthan polysaccharide and inorganic electrolytes

The effect of the electrolytes (MA: NaCl, MgCl₂ , PbCl₂ , and NaH₂PO₄ ) on the polymeric (a) weak-stabilization (PWST), (b) flocculation (PFL); and (c) stabilization (PST) of allophane in the presence of xanthan polysaccharide (GX), was investigated by electrophoretic mobility (EPM) measurements. At pH 6.5 (i.e.p.), with further addition of chlorides, the decrease in the absolute value of the negative EPM (|—EPM|) of allophane in 0.01 mm MA solutions indicated the suppression of PWST and PST, respectively, probably due to the decrease in the repulsive force originating from the negatively charged GX-chains with the addition of MA. By first addition of MA, the decrease in the |—EPM| value of allophane in 0.01 mm NaCl and MgCl₂ solutions also showed the suppression of PWST and PST. In 0.01 mm PbCl₂ and NaH₂PO. solutions, the increase in the EPM and |—EPM| values of allophane reflected the dispersion due to the specific adsorption of Pb₂₊ and H₂PO₄ - ions on the negatively and positively charged sites of the surface, respectively. At pH 4.5, the decrease in the |—EPM| value of allophane in 0.1 mm NaH₂PO₄ solution indicated the suppression of PST due to the specific adsorption of H₂PO₄ - ion on the positively charged surface of the particles. The absence of (i) PWST in the presence of GX and (ii) high stability in the presence of cationic lead species for the flocculated imogolite at pH 8.5 can be attributed to the tubular structure proposed by Cradwick et al. (1972: Nature (London) Phys. Sci., 240, 187-189), namely, to the difficulty in the development of a negative charge on the outer surface of its unit particle.     

Effect of particle size of halloysite on the deflocculation of mutual flocs of allophane and halloysite at pH 6.5 in dilute xanthan polysaccharide solutions

The effect of the particle size of halloysite on the deflocculation of mutual floes of allophane and halloysite in the presence of anionic xanthan polysaccharide was investigated spectrophotometrically. Although allophane which flocculated at the i.e.p. (pH 6.5) exhibited polymeric (i) weak-stabilization (PWST), (li) flocculation (PFL), and (iii) stabilization (PST) with increasing addition of xanthan, allophane and halloysite which flocculated mutually at pH 6.5 inhibited the deflocculation, viz., PWST and PST. Halloysite with a smaller average particle size (i.e., 0.08,um in average diameter) than the suspended microaggregates (SMAs) of allophane inhibited significantly the deflocculation, suggesting that the halloysite particles flocculated around the allophane particles. Halloysite with a larger average particle size (i.e., 0.2 μn in average diameter) than the SMAs of allophane slightly inhibited the deflocculation, suggesting that the halloysite particles were attached to the center of the flocculated SMAs of allophane. The inhibitory effects of particle arrangements on the deflocculation of the mutual floes of allophane-montmorillonite and allophanekaolinite were also investigated comparatively.     

Healed long-bone fractures in wild birds

AIM: To build a profi le of the oral lesions that occur in sheep in New Zealand that need to be considered within the differential diagnosis of foot-and-mouth disease.

METHODS: Lesions of the anterior lips and gums of sheep were surveyed in two abattoirs, photographed, and described grossly and histopathologically.

RESULTS: A sequence of lesions in order of age and stage of healing are described and illustrated, and their pathogenesis discussed. Lesions of the midline of the lips and gums of traumatic or irritant aetiology were common, and the prevalence was higher in adult sheep than in lambs.

CONCLUSIONS: The majority of lesions observed appeared to be primarily of traumatic aetiology. They probably arose from the fright/flight response behaviour of sheep, resulting in the mouth impacting against wire fences or yard railings while being handled. A smaller percentage of lesions may have been due to abrasive or irritant feed or soil. The presence of plant material and bacteria in lesions delayed healing and contributed to the formation of ulcers.