影响水产饲料水中稳定性的四大因素

来源： 赤峰和美嘉科技有限公司  点击：12次 发布时间：2016-9-19

水产颗粒饲料的水中稳定性是指饲料入水浸泡一定时间后，保持组成成分不被溶解和不散失的性能。一般以单位时间内饲料在水中的散失量与饲料质量之比来表示，也可用饲料在水中不溃散的最少时间来表示。通常要求鱼饲料的散失率小于20％(浸泡30min)。影响水产饲料水中稳定性的因素有：

一、粘合剂

 粘合剂是鱼用饲料中起粘合成型作用的添加剂，大致可分为天然物质和化学合成物质。前者按成份可分为糖类（淀粉、小麦粉、玉米粉等），和动物胶类（骨胶、皮胶、鱼浆等）；后者有羧甲基纤维素，聚丙烯酸钠等。在使用饲料生产过程中，添加适量的粘合剂可以提高饲料水中稳定性，粘合剂的粘合强度除与本身的性质有关外，还与饲料种类、加工条件等因素有关。

二、粉碎粒度

 粉碎细度对于鱼用饲料颗粒水中稳定性影响很大，原料粉碎粒度过大，其相应的表面积减少，导致原料表面上的淀粉在制粒调制过程中不能完全糊化，影响粘结作用，浸水后水分易浸入饲料颗粒而发生溃散。一般鱼用配合饲料的原料经粉碎后应通过40目标准筛，60目标准筛筛上物≤20%，而对虾饲料原料要求能通过60目标准筛。

三、调质

 饲料成型的关键在调质。调质是通过高温、高压的蒸汽作用于饲料，使淀粉糊化，蛋白质变性，增加其粘结性和可塑性，保证饲料结构细密，具有适当的硬度，水中稳定性好。为了起到调质的效果，除了掌握好调质时间，调质温度外，还应选用饱和蒸汽，并保持稳定、恒压，避免使用湿热蒸汽。对于粗蛋白≥30%的水产饲料，适宜的蒸汽压力为0.3-0.4MPa，调质温度80-95℃。

四、环模

 环模压缩比（深径/孔径）的大小对鱼饲料水中稳定性也有一定影响，压缩比大的环模压制出来的饲料颗粒硬度大，结构紧，饲料耐水时间长，反之则短，正常环模压缩比为14-17，对虾料17-20。

The English version

Aquatic particles feed water stability refers to the feed into the water after soaking time, maintain the performance of the components were not dissolve and is not lost. General feed per unit time in the water loss quantity and the quality of feed ratios, are also available to feed in the water not pieces to represent the minimum time. Usually require fish feed the loss rate of less than 20% (soak 30 min). Factors affecting the stability of the aquatic feed water are:

A, adhesives

Adhesive is bonded molding role in fish feed additives, can be roughly divided into natural substances and chemical substances. The former can be divided by ingredients, sugar, starch, wheat flour, corn flour, etc.), and animal glue, bone glue, hide glue, fish paste, etc.); The latter has a carboxymethyl cellulose, sodium polyacrylate, etc. In the process of the use of feed production, adding the right amount of binder can improve the stability of feed water, adhesive bonding strength in addition to the concerned with nature of itself, is also related to such factors as the type, feed and processing conditions.

Second, the crushing granularity

Grinding fineness for fish feed particles has great influence on the water stability, raw material grinding particle size is too large, the corresponding surface area to reduce, lead to the raw material on the surface of the starch in the process of granulating modulation is not fully gelatinization, binding effect, after flooding water immersion feed particles easily and happen to pieces. General fish with compound feed raw material after crushed by 40 goals screen, 60 goals must sieve sieve content 20% or less, and shrimp feed raw material requirements through 60 goals screen.

Third, quenched and tempered

The key on feed molding. Conditioning is applied to feed through high temperature and high pressure steam, the starch gelatinization, protein denaturation, increase the cohesiveness and plasticity, guarantee the fine feed structure, have moderate strength, water stability is good. In order to help the effect, in addition to mastering the tempering time, tempering temperature, also should choose saturated steam, and maintain a stable, constant pressure, avoid damp and hot steam. For aquatic feed crude protein 30% or higher, suitable for steam pressure of 0.3 to 0.3 MPa, tempering temperature 80-95 ℃.

Four, ring die

Ring die compression ratio (deep diameter/size) size also has a certain influence on the stability of fish feed water, large ring mould compression ratio of feed grain hardness, tight structure, feed water resistant time is long, short, conversely normal ring die compression ratio for 14 to 17, prawn 17-20.