农药对农产品营养和风味的影响

农药对防控农作物病虫草害、促进农产品高产贡献巨大,然而其大量使用常导致农产品农药残留、环境污染,同时还对农产品营养品质及风味造成影响,如改变农产品营养成分,导致农产品产生异味等变化等,应当引起重视。本文综述了农药对农产品营养物质及风味的影响及机制探究,以期为农产品安全及质量品质保障提供理论参考,为农药科学使用提供合理建议。开展农药对农产品营养品质及风味评价及作用机制研究,改善和提升农产品品质和营养水平,将是该领域未来研究的方向。     

Altering the ratio of dietary palmitic,stearic, and oleic acids in diets with or without whole cottonseed affects nutrient digestibility,energy partitioning,and production responses of dairy cows

The objective of this study was to evaluate the effects of varying the ratio of dietary palmitic (C16:0), stearic (C18:0), and oleic (cis-9 C18:1) acids in basal diets containing soyhulls or whole cottonseed on nutrient digestibility, energy partitioning, and production response of lactating dairy cows. Twenty-four mid-lactation multiparous Holstein cows were used in a split-plot Latin square design. Cows were allocated to a main plot receiving either a basal diet with soyhulls (SH, n = 12) or a basal diet with whole cottonseed (CS, n = 12) that was fed throughout the experiment. Within each plot a 4 × 4 Latin square arrangement of treatments was used in 4 consecutive 21-d periods. Treatments were (1) control (CON; no supplemental fat), (2) high C16:0 supplement [PA; fatty acid (FA) supplement blend provided ～80% C16:0], (3) C16:0 and C18:0 supplement (PA+SA; FA supplement blend provided ～40% C16:0 + ～40% C18:0), and (4) C16:0 and cis-9 C18:1 supplement (PA+OA; FA supplement blend provided ～45% C16:0 + ～35% cis-9 C18:1). Interactions between basal diets and FA treatments were observed for dry matter intake (DMI) and milk yield. Among the SH diets, PA and PA+SA increased DMI compared with CON and PA+OA treatments, whereas in the CS diets PA+OA decreased DMI compared with CON. The PA, PA+SA, and PA+OA treatments increased milk yield compared with CON in the SH diets. The CS diets increased milk fat yield compared with the SH diets due to the greater yield of de novo and preformed milk FA. The PA treatment increased milk fat yield compared with CON, PA+SA, and PA+OA due to the greater yield of mixed-source (16-carbon) milk FA. The PA treatment increased 3.5% fat-corrected milk compared with CON and tended to increase it compared with PA+SA and PA+OA. The CS diets increased body weight (BW) change compared with the SH diets. Additionally, PA+OA tended to increase BW change compared with CON and PA and increased it in comparison with PA+SA. The PA and PA+OA treatments increased dry matter and neutral detergent fiber digestibility compared with PA+SA and tended to increase them compared with CON. The PA+SA treatment reduced 16-carbon, 18-carbon, and total FA digestibility compared with the other treatments. The CS diets increased energy partitioning toward body reserves compared with the SH diets. The PA treatment increased energy partitioning toward milk compared with CON and PA+OA and tended to increase it compared with PA+SA. In contrast, PA+OA increased energy partitioned to body reserves compared with PA and PA+SA and tended to increase it compared with CON. In conclusion, milk yield responses to different combinations of FA were affected by the addition of whole cottonseed in the diet. Among the combinations of C16:0, C18:0, and cis-9 C18:1 evaluated, fat supplements with more C16:0 increased energy output in milk, whereas fat supplements with more cis-9 C18:1 increased energy storage in BW. The combination of C16:0 and C18:0 reduced nutrient digestibility, which most likely explains the lower performance observed compared with other treatments.     

于都黄麟-祁禄山地区土地质量地球化学评价

通过对于都县黄麟-祁禄山地区开展1:5万土地质量地球化学调查,在野外土壤样品采集和化验测试的基础上,系统地研究了影响土地质量的各项地球化学指标特征与控制因素,基本查明有益元素、重金属元素分布,划分出重点污染区和绿色土地发展区,并进行土地质量等级评价,为永久基本农田建设、土地资源开发与利用等方面提出建议。     

泡叶藻的营养成分分析及评价

为评估泡叶藻的营养价值，对泡叶藻的主要营养成分、氨基酸组成、脂肪酸组成、无机元素、重金属、褐藻胶和甘露醇等含量进行检测和分析。结果表明，泡叶藻的主要成分为总膳食纤维，含量为40.68%，其中可溶性膳食纤维含量8.54%；粗蛋白含量9.66%，检测出18种氨基酸，氨基酸总含量为7.99 g/100 g，其中必需氨基酸占氨基酸总量的为37.90%，呈味氨基酸占氨基酸总量的40.25%，第一限制性氨基酸为苏氨酸，氨基酸评分134.98，氨基酸组成比例均衡；粗脂肪含量1.53%，其中不饱和脂肪酸占总脂肪酸总量的43.92%；灰分含量39.43%，常量元素K、Na、Ca和微量元素Fe、Zn、Sn等含量丰富；褐藻胶和甘露醇含量高。综上，泡叶藻是一种高膳食纤维、高蛋白、低脂肪的藻类，在食品、海藻化工和饲料领域具有较高开发利用价值。     

暗色等刺参(Isostichopus fuscus)营养成分分析

目的测定暗色等刺参的主要营养成分,评价其营养价值。方法分别采用凯氏定氮法、高温灼烧法、亚甲基蓝比色法测定海参中的粗蛋白、灰分、海参多糖含量,采用氨基酸自动分析仪测定氨基酸组成,采用电感耦合等离子体质谱法测定常量、微量无机元素。结果暗色等刺参的海参多糖含量为8.04%,蛋白质含量高达83.35%,且氨基酸组成丰富,其中甘氨酸、谷氨酸、丙氨酸含量相对较高。暗色等刺参富含人体所需的多种矿物质元素,常量元素中Ca、Mg含量较高,微量元素中Fe、Zn的含量较高。结论暗色等刺参富含蛋白质、海参多糖以及人体所需的无机元素,具有较高的食用价值和开发利用前景。     

马氏珠母贝综合利用的研究进展

马氏珠母贝是我国南方沿海地区人工养殖生产珍珠的主要贝类,目前已在养殖生态、插核育珠、营养成分和生物活性等方面对其进行了广泛的研究。文章综述马氏珠母贝所育珍珠、贝壳和贝肉营养成分、生物活性分析及其应用等方面的研究进展,为马氏珠母贝的进一步研究利用提供理论依据。