Chinese food adsorbents: technologies and trends? 

When you hear “Chinese food adsorbents”, the first thought for many is “silica gel”. in bags with shoes or cheap fillers. This is where the main gap in perception lies. Yes, the mass segment exists, but for ten years now another race has been going on behind it - for purity, selectivity and functionality. If previously the main thing was to “absorb moisture?” at any cost, then now it all comes down to what exactly and how exactly you absorb, without affecting the product itself. My first deliveries in the 2010s ran into this wall of misunderstanding: the client wants an adsorbent to protect expensive spices from odors, but they bring him standard silicon oxide, which can “eat” the aroma of the spice itself. I had to figure out in practice what was what.

From silica gel to molecular sieves: evolution or revolution?

Let's start with the base. Traditionalsilica gelis still a working soldier, especially in the segment of dry food packaging with a long shelf life. But his problem is non-selectivity. It loves water, but it can also pick up volatile organic compounds. A project for a large tea manufacturer in Fuzhou encountered exactly this: a batch of expensive jasmine tea lost its top notes of aroma after transportation. They blamed the packaging, but the reason turned out to be too active, “aggressive?” silica gel in a desiccant bag. This was a typical case when the technical parameters for moisture absorption were ideal, but the practical result was a failure.

This is where zeolites and modified molecular sieves come into play. Their beauty lies in their controlled porosity. Can I “customize” it? pore size so that it traps water molecules (about 2.8?), but allows larger flavor molecules to pass through. This is no longer just an adsorbent, but a tool for fine-tuning the quality of the product. Chinese manufacturers, especially those that work at the intersection of chemistry and food engineering, such as institutes at large chemical holdings, are now actively developing this area. I won’t hide the fact that the first examples of such “smart” ones. The zeolites I worked with about 8 years ago suffered from problems with batch uniformity - one batch works great, another is ?fonit? microimpurities. Now, fortunately, control has been established.

An interesting trend in recent years is hybrid materials. For example, a base made of the same silica gel, but with trap molecules immobilized on the surface for specific substances, say, for ethylene released by fruits. This is closer to active functional packaging. I saw developments fromChengdu Yizhi Technology Co.(their website, by the way,https://www.yzkjhx.ruit is useful to look at to understand the scale of R&D in this area), where they position themselves not as sellers of powders, but as a design institute that solves specific problems of food stabilization. This is an important shift in thinking from selling a chemical to selling a technology solution.

?Natural? vs. ?Effective?: the battle for the premium segment

Request for ?clean label? (clean label) also reached adsorbents. More and more often it sounds: “Do you have something based on natural materials?” And this is where things get interesting. Activated carbon made from bamboo or coconut shells is a classic. But its use in food is limited due to its strong coloring ability and the same non-selectivity. It’s difficult to “fit in” him. in transparent packaging or use without staining the product.

The direction of adsorbents based on modified starches or chitin seems more promising. They work more softly, can be transparent in gel form and are psychologically better perceived by the consumer. But their capacity and adsorption rate, especially in conditions of high humidity, are often inferior to synthetic analogues. I had experience with the supply of starch microspheres to protect dried truffles in vacuum packaging. The idea was brilliant - an all-natural system. In practice, when there was a sudden change in temperature during logistics, the adsorption capacity dropped and condensation formed on the inside of the package. The client was furious. We had to urgently look for a compromise option - a combined layer of natural and synthetic material.

This case well illustrates the main conflict: marketing requires “naturalness,” while the physics of the process and the economics of logistics require guaranteed efficiency. Now the trend among advanced players is not to choose one side, but to create hybrid systems and honestly convey to the customer the principle of operation: “Here we have a natural component to control light volatile substances, and here we have a highly effective synthetic module for guaranteed moisture retention, but it is physically separated from the product by a barrier layer?” This requires the manufacturer to have a deep understanding of both packaging technology and chemistry.

Regulatory reefs: FDA, TR CU and “non-food” origin

Technology is one thing, but getting a product onto the market is a completely different story. One of the most common and painful problems when entering the international market (not only Russian) with Chinese adsorbent is documenting the nutritional status of all components and the production process. Many high-quality adsorbents are born in the depths of the chemical industry, and the chain of raw materials can be traced back to the original “food grade” one. source can be difficult.

For example, silicon dioxide (E551) - it would seem that everything is simple, it is allowed everywhere. But if it is produced from technical raw materials, which could contain impurities of heavy metals, then the entire batch may be rejected. I had a precedent when, in order to deliver to the EAEU, I had to literally “excavate” for customs and Rospotrebnadzor, the history of raw materials: from the quarry where quartz sand was mined to certificates for each stage of purification. The manufacturer in China at first did not understand why this was needed - they have a general quality certificate! But for food applications, it is traceability that is needed.

Now smart players like the one mentionedChengdu Yizhi Technology Co., Ltd., created on the basis of Huaxi Technology, immediately put this into the process. Their status as a design institute with a registered capital of 120 million yuan allows them to invest not only in R&D, but also in the construction of such “white” ones. chains and obtaining international certificates. This becomes their competitive advantage over small factories. For us, as importers, working with such a supplier reduces risks, although the price may be higher. But saving on food safety costs you more.

Logistics and form: from bags to “smart” ones packages

This is rarely written about in reviews, but a lot depends on the form of delivery of the adsorbent. Buying tons in big bags is cheaper, but then you need to decide how to dose it, package it and implement it into the customer’s line. Dustiness is a separate headache for food processing plants. Therefore, there are more and more requests for ready-made solutions: not powder, but already formed sachet packages, tablets, capsules, or even adsorbent inserts in the lid.

Here China has made a huge leap. If previously the equipment for the production of sachets was European, and the filler was Chinese, now completely local integrated solutions have appeared. I saw lines that form, fill and seal sachets with dosage accuracy down to the milligram, and in an atmosphere of inert gas, so that the adsorbent does not start working before it gets into the packaging with the product. This is critical for highly active materials.

But there are pitfalls here too. One day they brought a batch of these sachets for meat delicacies. Everything was excellent: paper with the required permeability and high quality adsorbent. But the glue used to seal the edge of the sachet caused a slight migration of odor upon prolonged contact with the fat of the product. The product was not spoiled, but the organoleptic examination detected an alien tint. I had to urgently change the supplier of the adhesive composition. Conclusion: an adsorbent is a system where everything is important, even what, it would seem, is not directly related to it.

A look into the future: adsorbents as a diagnostic tool

The most interesting trend that is just emerging is the transition from passive protection to active monitoring. Imagine an adsorbent layer that not only absorbs harmful gases (ammonia, hydrogen sulfide), but also changes color when a certain saturation threshold is reached. This is no longer just protection, but an indicator of product freshness for logistics, retail and even for the end consumer.

In China, such developments are carried out in several laboratories, including in collaboration with large food corporations. It is still expensive and difficult for mass implementation. The main problem is the stability of the indicator. It must react strictly to the target substance and not change color, say, from changes in temperature or light. But the potential is huge. This could radically reduce food waste by providing an objective, not just dated, assessment of freshness.

Another direction is adsorbents with prolonged and controlled release. It’s not easy to absorb something bad, and then, when conditions change (for example, microwave heating), release a beneficial substance - an antioxidant, a flavoring. It sounds like science fiction, but patents are already being filed. I believe that in five to seven years we will see the first commercial applications. In the meantime, the main task for the industry is to bring to fruition and massize those hybrid and selective solutions that I spoke about above. The main thing is to get away from the perception of Chinese food adsorbent as a cheap consumable. Now it is often a high-tech, engineered product that requires deep integration into the food production and packaging process. And those who understand this receive a serious advantage.