Effects of replacing maize silage with lucerne silage and lucerne silage chop length on rumen function and milk fatty acid composition

The objective of this study was to investigate whether higher lucerne (Medicago sativa; alfalfa) silage inclusion rate and longer lucerne chop length improves rumen function through increased provision of physically effective fiber, when included in a maize and lucerne silage-based total mixed ration. Diets were formulated to contain a 50:50 forage:concentrate ratio [dry matter (DM) basis] and be isonitrogenous and contain equal levels of neutral detergent fiber (320 g/kg). The forage portion of the offered diets was composed of maize and lucerne silage DM in proportions (wt/wt) of either 25:75 (high lucerne; HL) or 75:25 (low lucerne; LL). Second-cut lucerne was harvested and conserved as silage at either a long (L) or a short (S) chop length (geometric mean particle lengths of 9.0 and 14.3 mm, respectively). These variables were combined in a 2 × 2 factorial arrangement to give 4 treatments (HLL, HLS, LLL, LLS), which were fed in a 4 × 4 Latin square design study to 4 rumen-cannulated, multiparous, Holstein dairy cows in mid lactation. Effects on DM intake, chewing behavior, rumen volatile fatty acid concentration, rumen pH, rumen and fecal particle size, milk production, and milk fatty acid profile were measured. Longer chop length increased rumination times per kilogram of DM intake (+2.8 min/kg) relative to the S chop length, with HLL diets resulting in the most rumination chews. Rumen concentrations of total volatile fatty acids, acetate, and n-valerate were higher for the HLS diet than the other 3 diets, whereas rumen propionate concentration was lowest for the HLL diet. Physically effective fiber (particles >4 mm) percentage in the rumen mat was increased when L chop length was fed regardless of lucerne inclusion rate. No effect of treatment was observed for milk yield, although milk protein concentration was increased by L for the LL diet (+1.6 g/kg) and decreased by L for the HLL diet (?1.4 g/kg). Milk fat concentrations of total cis-18:1 (+3.7 g/100 g of fatty acids) and 18:3 n-3 (+0.2 g/100 g of fatty acids) were greater with HL. In conclusion, longer lucerne silage chop length increased time spent ruminating per kilogram of DM intake, but had no effect on rumen pH in the present study. Increasing dietary lucerne inclusion rate had no effects on rumination activity or rumen pH, but decreased the ratio of n-6:n-3 polyunsaturated fatty acid concentrations in milk fat.     

发酵番茄汁饮料的研究进展

阐述了近年来国内外番茄制品的发展过程,并对新型番茄制品——番茄汁发酵饮料的研究进展进行了阐述。     

草莓汁发酵乳饮料的研制

研制了一种以发酵乳和草莓汁为主要原料加工调制成的发酵乳饮料,在确定饮料所含发酵乳量（添加量定为35%）的基础上,阐述了草莓汁发酵乳饮料的生产工艺和最佳配方.得出最佳工艺配方为：发酵乳35%、草莓汁15%、白砂糖10%、复合稳定剂0.6%、酸液0.2%、适量的香精（均为质量分数）.     

Effects of extraction and reconstitution of ryegrass juice on fermentation,digestion and in situ degradation of pressed cake silage

Primary growth of Italian ryegrass was fractionated into green juice and pressed cake (PC). PC was ensiled either directly or after reconstitution with the juice which was spray dried and then added to water before ensiling (RPC). This process was aimed at distinguishing between chemical (removal of nutrients) and physical (mechanical disintegration) effects of fractionation. Two additional wilted silages were prepared from long cut or chopped Italian ryegrass (WL and WC, respectively). The fermentative quality, digestion and in situ degradation of dry matter for the four silages were compared. WC, RPC and PC silages indicated lactate-rich fermentation while WL silage had a comparatively low lactate content. PC silage had a lower (P<0·05) pH value with lower (P<0·05) amounts of organic acids compared with WC and RPC silage, suggesting that removal of buffering components with the juice had greater effects than shredding on fermentation of PC silage. The digestibility of protein was lower (P<0·05) in PC than WL silage but the reduction was compensated for in RPC silage. Ruminal concentrations of total volatile fatty acids were the highest (P<0·05) when goats fed WL silage while those on the other silages had similar concentrations. Ruminal pH was lower (P<0·05) in goats fed PC than WC silage and the difference was not fully reversed by reconstituting the juice to PC. Juice extraction decreased (P<0·05) the soluble fraction and the rate of disappearance of dry matter in the rumen but the potential degradability was not different among treatments. These results suggest that both chemical and physical changes due to the fractionation affect the characteristics of digestion of PC silage while the removal of nutrients has a major role in the modified silage fermentation. © 1997 SCI.     

国外苹果发酵汁加工现状和趋势

回顾并概要介绍了近年来国际苹果发酵汁饮料的加工技术、研究状况和发展趋势。     

蜂蜜-柿子汁发酵饮料的研制

研究了蜂蜜、柿子汁发酵饮料的制作工艺及酵母菌、醋酸菌接种量、醋酸发酵温度和发酵时间对产品感官质量的影响。结果表明:含糖量25%的蜂蜜、柿子汁为原料,接种3%的酵母菌种子液,28℃发酵4d,然后接种5%的醋酸菌种子液,32℃条件下发酵6d得到的发酵饮料,具有蜂蜜和柿果的清香味,质量和口感最好。     

泡菜乳酸菌发酵蔬菜汁的研究

对从泡菜中分离出的三株乳酸菌H-1,G-1,X-1,选择了其最适扩大培养基,研究了乳酸发酵蔬菜汁生产中的添加剂对三株乳酸菌生长的影响,并对乳酸发酵蔬菜汁工艺进行了优选。     

固定化细胞混合发酵黄瓜汁饮料的研究

以黄瓜汁为主要原料,进行多菌种固定化混合发酵蔬菜饮料的研究,结果表明,乳酸菌和醋酸菌以１．５％浓度的海藻酸钠固定化包埋为宜,固定化乳酸菌和醋酸菌最佳体积比为１∶２,接种量为２０％,发酵温度２８℃,发酵时间２ｄ。     

The effects of sorbates on the ensilage of chopped whole-plant maize and lucerne

The incorporation of (a) sorbic acid (0.18 and 0.90 g kg^?1, fresh weight basis) and potassium sorbate (0.90 g kg^?1) with chopped lucerne, and (b) sorbic acid (0.90 g kg^?1) and potassium sorbate (0.90 g kg^?1) with chopped maize (whole-plant) at the time of ensiling, led to a reduction in the surface spoilage associated with the ensilage of these two forages. Use of sorbic acid (0.90 g kg^?1) and potassium sorbate (0.90 g kg^?1) led to (a) a reduction of volatile nitrogen (VN), higher levels of residual water-soluble carbohydrates (WSC) in lucerne silage and more aerobically stable lucerne silage and (b) a reduction in weight loss, population of yeasts and moulds, and VN, higher levels of WSC in maize silage and more aerobically stable maize silage when compared to the untreated forages or forages treated with sorbic acid and potssium sorbate at 0.045 and 0.18 g kg^?1 (fresh weight basis), respectively.     

无醇及低醇发酵果汁研究进展

简述了无醇及低醇发酵果汁的特点，重点介绍了无醇及低醇发酵果汁的生产工艺与国内外研究进展，并针对目前低醇果汁生产中存在的问题提出了相应的建议。     

Ozonated cotton stalks as a silage additive: Fermentation data on lucerne with particular reference to protein degradation

Fermentation patterns of lucerne silages were studied in laboratory silos. The treatments consisted of: (a) fresh (200 g kg>^?l DM) lucerne, ensiled without any treatment (L); (b) lucerne wilted to 525 g kg^?1 DM prior to ensilage (WL); (c) fresh lucerne + cotton stalks at a ratio of 60:40 on a dry matter (DM) basis (L + CS); and (d) fresh lucerne + ozone-treated cotton stalks at the same ratio as above (L+O₃). Silos were opened after 90 days and the silages analysed. The highest DM loss was found in the L silage (14·7%), whereas in the L+O₃ silage DM loss was practically nil. Both wilting and the addition of untreated cotton stalks proved to be effective in reducing DM losses during fermentation. The production of lactic acid and volatile organic acids in the L+ O₃ and WL silages was lower than in the L and L+CS silages. The poorest ability to preserve forage protein was found in the L silage, in which only 28 % of the protein was recovered after 90 days. The greatest ability to preserve protein was found in the L+O₃ silage, in which 78 % of the protein was maintained. Ammonia production followed generally similar patterns. Amino acids underwent extensive degradation in the L silage. Recovery of amino acids in the WL silage was in the range 69–93 %, and in the L + O₃ silage it was almost complete. Ozonated CS proved to be a good silage additive with respect to energy and protein preservation. Its future use in the field would allow direct ensilage of fresh leguminous material immediately after harvest, producing a high quality silage.     

浓缩果汁及其发酵酒的研究进展

阐述了浓缩果汁的特性，以及常用浓缩技术的优缺点，综述了以浓缩果汁为原料发酵果酒的研究现状，并展望了以浓缩果汁为原料发酵果酒的研究方向。     

发酵乳清橘汁饮料的研制

以乳清粉为原料,经过蛋白澄清后添加干酪乳杆菌进行发酵。先在单因素实验基础上,以DPPH自由基清除率为指标,通过正交试验获取发酵乳清的最佳工艺参数;然后加入稳定剂和调味料制备具有抗氧化性的饮料,并通过正交试验优化制备抗氧化乳清发酵饮料的工艺配方。结果表明最佳工艺配方为:干酪乳杆菌浓度4%、乳清底物浓度10%、发酵温度为41℃、发酵时间8h、黄原胶0.3%、橘汁添加量4%、蔗糖添加量6%;最后制得的产品色泽乳黄、酸香浓郁,综合得分为82.6,DPPH自由基清除率为47.86%。      

杀菌处理对发酵红枣汁品质的影响

目的:对比不同杀菌方式对发酵红枣汁品质的影响。方法:红枣汁发酵前，采用低温等离子体杀菌(CPS)和脉冲强光杀菌(PLS)对发酵前后红枣汁品质的影响，以高压杀菌(SA)红枣汁为对照。结果:采用CPS处理，红枣汁发酵前后总糖、还原糖和可溶性固形物含量均显著高于另外两种杀菌方式，发酵后红枣汁的总糖、还原糖和可溶性固形物含量分别为1.7 mg/L、1.64 mg/L和12.4%;采用SA处理，红枣汁发酵前后总酚含量均为最低，发酵后红枣汁的总酚含量仅为2.19 mg/L;采用PLS处理，红枣汁发酵前后的色差值变化最小。经CPS、PLS和SA处理后的红枣汁，接种植物乳杆菌发酵48 h后，其活菌数均>6.48 lg(CFU/mL),其中，PLS处理后植物乳杆菌活菌总数最高[6.63 lg (CFU/mL)]。结论:非热杀菌处理(特别是PLS)对发酵红枣汁的品质影响较小，可作为发酵红枣汁加工中的杀菌处理技术。     

多菌种发酵辣椒汁培养基配方的优化

以肠膜明串珠菌（Leuconostoc mesenteroides）、植物乳杆菌（Lactobacillus plantarum）、发酵乳杆菌（Lactobacillus fermentum）和嗜酸乳杆菌（Lactobacillus acidophilus）为试验菌株,采用鲜辣椒汁为基础培养基,通过单因素试验确定最佳碳源、氮源和无机盐及其添加量。在此基础上,以上4种乳酸菌按照1∶1∶1∶1的配比混合后作为试验菌株,采用正交试验设计优化,多菌种发酵鲜辣椒汁培养基的配方。结果表明,最佳培养基配方为葡萄糖的添加量为4%,酵母浸膏的添加量为3%,磷酸氢二钾的添加量为0.2%,优化后培养基中乳酸菌浓度为8.45×109 CFU/mL,增殖效果良好。该研究为剁辣椒的产业化生产奠定了基础。     

Ensiling characteristics and ruminal degradation of Italian ryegrass and lucerne silages treated with cell wall-degrading enzymes

Two experiments were carried out to investigate the effect of added cell wall-degrading enzymes at ensiling on the fermentation and in situ degradation of grass and legume silages. Primary growths of Italian ryegrass (Lolium multiflorum Lam) and lucerne (Medicago sativa L) were wilted and ensiled in laboratory-scale silos with or without enzymes. Silages were opened at 2, 5, 15 and 45 days after storage; the fermentation quality and the contents of cell wall components (NDF, ADF, ADL) were determined. The 45 day silages were subjected to in situ incubation experiments, and the kinetics of DM and NDF degradation was estimated. The enzyme treatment enhanced the lactic acid production (P < 0.01) and reduced the pH value (P < 0.01) of both Italian ryegrass and lucerne silages. The contents of cell wall components, however, were not affected by enzymes, except for NDF of Italian ryegrass silage. The in situ incubation experiments revealed that added enzymes increased the rapidly degradable DM (P < 0.01) and appeared to decrease the rate of degradation of DM and NDF of Italian ryegrass silage. The rapidly degradable DM was not altered when lucerne was treated, but the rate of degradation of NDF was significantly reduced (P < 0.05). These results suggest that although added cell wall-degrading enzymes could improve the preservation of grass and legume silages, the effects on ruminal degradation may be different according to the herbage treated. Enzymatic hydrolysis during ensilage may be restricted to easily digestible cell walls, leaving relatively less digestible components that would be retained in treated silages. © 1999 Society of Chemical Industry     

乳酸菌发酵红树莓山楂复合果汁品质分析

采用植物乳杆菌（Lactobacillus plantarum）、鼠李糖乳杆菌（Lactobacillus rhamnosus）、副干酪乳杆菌（Lactobacillus paracasei）三种乳酸菌按照1∶1∶1的比例复合发酵红树莓山楂复合果汁（1∶1）,分析其发酵前后部分理化指标的变化。结果显示,发酵后红树莓山楂复合发酵饮料中含有16种氨基酸;共检出40种挥发性风味物质,主要为酯类、酮类、酸类以及酚类化合物等;总酚含量为0.061 g/100 g、维生素C含量为89.56 mg/100 g;发酵后有机酸含量增至4.19 g/L,特别是乳酸含量由0.12 g/L增至3.22 g/L;活菌数达到2.2×107CFU/m L。感官分析结果显示,乳酸菌发酵能提升发酵原液的风味,保护色泽,红树莓山楂复合发酵饮料感官评分为86分,是一款营养、健康的乳酸发酵饮料。     

发酵果汁啤酒的研制

介绍了以果汁、麦汁为原料,以啤酒酵母为菌种,通过低温发酵研制成果汁啤酒的方法。研究表明果汁麦汁以61混合较好,对发酵液进行调配时,酒精度3%(V/V),糖度5.5°Bx,pH值4.4,最终产品可以形成令人满意的风味。     

发酵果蔬汁功能特性及生物转化研究进展

多酚具有抗氧化、抗肿瘤、抗动脉硬化、抗炎、抗病毒等生理药理活性,这些健康效应取决于人体对其生物利用度。虽然食品中天然多酚的含量很高,但由于多酚的大分子、稳定性低、被动扩散等原因,其利用率很低。乳酸菌是肠道益生菌,能产乳酸及促进营养物质的吸收,具有抗氧化、抑菌等功能,广泛用于发酵果蔬汁。乳酸菌发酵可将结合酚转化为更易被人体吸收利用的游离酚,提高多酚的生物利用度。该文对乳酸菌发酵果蔬汁中多酚成分经乳酸菌发酵进行代谢转化,提高多酚生物利用度等问题进行综述,以期为开发益于人体健康的发酵果蔬汁提供依据。