抗性淀粉的分类与选择

最近抗性淀粉火爆食品生产和消费端，但是抗性淀粉的分类和选择上大家还不是很清楚，北京祥玉作为抗性淀粉全球供应商，简单做个说明以便于大家的选择。

我们通俗理解，抗性淀粉就是抵抗消化淀粉，基于自身的分子、晶体结构难以被消化，满足了大家的食欲但又不产生过量糖粉，从而食先减肥、控血糖，又是益生元实现肠道保健等作用。

抗性淀粉常见分类是生产来源标准，不是品质分类，即RS1-2-3-4-5。

RS1叫作物理包埋，简单说就是谷物粗加工，极端理解谷物整颗粒人体无法代谢，长期摄入导致消化系统损伤，没有实际意义。

RS2叫天然谷物来源抗性淀粉，是指谷物淀粉天然具有抗消化能力，核心在于淀粉颗粒硬、内部分子紧致，淀粉酶很难作用，通常的食品加工无法糊化，从而形成了难消化特征。RS2是全球最主要的商业化抗性淀粉类型。产量高、价格低、性能稳定，纯天然无副作用。

RS3则是老化回生淀粉，是淀粉加热先糊化（糊精化）再冷却重新结晶，即常说的冷米饭。老化回生淀粉最大的问题是，重结晶强度不够，导致膳食纤维不高；耐热性差，遇热即二次糊化快速转化为葡萄糖。比如，凉皮、粉条就是淀粉回生产物，凉皮、粉条不能减肥。冷米饭也是一个道理。其次是，成本高、工艺稳定性差。精选特殊原料、再加热、再冷却，听起来就很贵，而且产品标准很难掌握精准。所以，全球范围内RS3产品很少，主流产品还在RS2基础上生产，且更多的是为了满足法规要求降低膳食纤维含量。

RS4则是化学变性的，性能最好、性价比最高，膳食纤维最高耐热性最稳定，但属于食品添加剂，使用受限。

RS5则是一个较新的工艺路径，是在RS4基础上的衍生工艺，即用有机质基团替代化学成分生产变性淀粉，避免食品添加剂的限制。当前来看无机质化学分子的稳定性还是远超有机质分子。这个理解起来并不难，蛋白脂、脂肪酸等的抗高温、高压能力比磷酸、醋酸差多了，所以实际无量产产品。

我们理解抗性淀粉分类是生产工艺分类，不是功能、功效分类，并非代数越大就越好。那么如何选择抗性淀粉呢？

首先，看膳食纤维含量。抗性淀粉是淀粉的一种，所以是大分子多糖结构。因为不被小肠利用消化，不能转化成葡萄糖，就归入了不可利用碳水，即膳食纤维。所以，抗性淀粉体重的最主要营养是膳食纤维。

北京祥玉的系列抗性淀粉膳食纤维均在50%以上，折干基计算均在60%以上，部分超80%。以这个标准，生土豆、冷大米就直接排除。生土豆、冷大米的膳食纤维含量可以界定为0，而且为了这一点膳食纤维消费者要吃超过平时正常摄入量的食物，适得其反。从另一个角度评估，全球范围内的主食首先是提供热量，其次是产量高。土豆是西方主食、大米是东南亚主食，理论上不可能是膳食纤维。

其次，耐热性即糊化温度。所有的有机质均有耐加工指标，也就是加工后的分子稳定性。所以，抗性淀粉的第二关键在于耐热性，也就是在多少温度范围内不被分解，淀粉学称糊化（糊精前状态）。同时，我们要明确任何类型的抗性淀粉均有糊化温度，均会糊化。这也是所有物料均会存在的问题，就是钢铁也有熔化温度失去强度。所以，选择抗性淀粉要看糊化温度，即通常加工环境下，不糊化或者糊化度越低越好。从这个角度评估RS4最强。

北京祥玉（www.beijingxiangyu.cn)的系列抗性淀粉，完成糊化均需要在高水分（5%以内浓度）背景下，超过100度，不糊化就难以吸收。这也解释了，抗性淀粉糊化后性能损失，但为什么能减肥？是因为现有的食品加工根本无法让北京祥玉的抗性淀粉糊化。用这个指标评估RS3，大部分RS3的糊化温度不高，也是为什么大部分RS3生产固体饮料还可以，生产主食烘焙效果较差的原因。评估糊化程度，简单的方式是，沸水冲调看颜色和粘度，颜色越透明、粘度越大说明糊化度越高，反之越白、流动性越好，则糊化度越高。北京祥玉抗性淀粉，用沸水冲调，呈现出白色悬浮乳液状态，如同牛奶。

Classification and Selection of Resistant Starch

Resistant starch has become extremely popular across food manufacturing and consumer markets recently. However, many people remain unclear about its categories and selection criteria. As a global supplier of resistant starch, Beijing Xiangyu hereby provides a straightforward guide to facilitate your product selection.

In layman’s terms, resistant starch refers to starch that resists human digestive breakdown. Owing to its unique molecular and crystalline structure, it is hard to digest. It satisfies appetite without generating excessive blood glucose, supporting weight management and glycemic control. Meanwhile, it acts as a prebiotic to boost intestinal health.

Resistant starch is categorized by manufacturing and source standards into five types: RS1, RS2, RS3, RS4 and RS5. This classification system does not represent grading by product quality.

RS1: Physically Encapsulated Resistant Starch

This type is derived from coarsely processed whole grains. In an extreme scenario, intact grain particles cannot be fully metabolized by the human body. Long-term intake may cause damage to the digestive tract, so RS1 bears little practical application value.

RS2: Natural Grain-Sourced Resistant Starch

It naturally forms within grain starch granules, featuring rigid, tightly packed internal molecules that resist amylase degradation. It cannot gelatinize under conventional food processing, resulting in its indigestible properties. RS2 is the world’s dominant commercial resistant starch variant, characterized by high output volume, low cost, stable performance and fully natural composition with no side effects.

RS3: Retrograded (Retrograded) Starch

Retrograded starch is produced via a two-step process: starch is first heated for gelatinization, then cooled down to recrystallize. Cold cooked rice is a typical daily example. It has two major drawbacks:

1. Weak recrystallization leads to low dietary fiber content and poor heat resistance. It undergoes secondary gelatinization and rapidly converts to glucose upon reheating. Products such as cold rice noodles and starch sheets fall into this category and deliver no weight-loss benefits.
2. High production cost and unstable manufacturing consistency. Production requires special raw materials plus repeated heating and cooling procedures, driving up costs, while finished product indicators are difficult to precisely control. Globally, RS3 products account for a tiny market share. Most commercial products are based on RS2 formulations; RS3 is only occasionally added merely to meet regulatory fiber content thresholds, without boosting actual dietary fiber levels.

RS4: Chemically Modified Resistant Starch

It boasts optimal performance and cost-effectiveness, with the highest dietary fiber content and superior heat stability. However, it is classified as a food additive, subject to strict usage limitations in food production.

RS5: New Modified Resistant Starch Derived from RS4

RS5 is an improved variant of RS4, manufactured by replacing inorganic chemical modifiers with organic functional groups to bypass food additive restrictions. Nevertheless, organic molecules are far less stable than inorganic chemical structures. Lipids, fatty acids and similar organics exhibit much poorer resistance to high temperature and high pressure compared with phosphate or acetate modifiers. At present, no mass-produced commercial RS5 products are available worldwide.

Key Takeaway

The RS1–RS5 classification is based on production processes, not functional efficacy. A higher RS serial number does not equal better performance. Below are core criteria for selecting resistant starch:

1. Dietary Fiber Content

Resistant starch is a high-molecular-weight polysaccharide. Since it cannot be digested and converted into glucose in the small intestine, it is classified as unavailable carbohydrates, namely dietary fiber — the core nutritional component of resistant starch for weight management. All resistant starch series from Beijing Xiangyu deliver dietary fiber content above 50%, exceeding 60% on a dry basis, with some grades surpassing 80%. By this benchmark, raw potatoes and cold rice can be ruled out directly, as their effective dietary fiber content is near zero. Consumers would need to consume abnormally large portions to gain trivial fiber intake, which backfires on weight management. From a broader perspective, staple foods worldwide are designed primarily to supply calories with high yields; potatoes (Western staple) and rice (Southeast Asian staple) cannot function as high-fiber ingredients by nature.

2. Heat Resistance (Gelatinization Temperature)

All organic raw materials have processing tolerance limits, measured by molecular stability under heat — defined as gelatinization temperature in starch science, the temperature at which starch breaks down. All resistant starch variants will gelatinize once exceeding their threshold temperature (similar to metals melting at specific temperatures and losing rigidity). When selecting products, prioritize resistant starch with high gelatinization temperatures that remain minimally gelatinized under standard food manufacturing conditions. RS4 ranks top in heat resistance in this regard.

All resistant starch products from Beijing Xiangyu (Official Website: www.beijingxiangyu.cn) only fully gelatinize under two strict conditions: moisture content lower than 5% and temperature over 100 °C. Conventional food processing cannot meet such harsh criteria, so their functional properties remain intact during production — this explains why our resistant starch retains weight-loss benefits after food manufacturing. By contrast, most RS3 varieties have low gelatinization temperatures, making them suitable only for powdered solid beverages but poor for baked staple foods.

Simple Home Test to Judge Gelatinization Degree

Mix the sample with boiling water and observe its appearance and viscosity:

• Transparent solution + high viscosity = high gelatinization degree
• Opaque white suspension + good fluidity = low gelatinization degree When mixed with boiling water, Beijing Xiangyu’s resistant starch forms a milky white suspended emulsion similar to fresh milk, indicating minimal gelatinization.