02/03/2023

Grinding: A fundamental point in the manufacture of extruded dry food for cats and dogs

By Ludmila Barbi T. Bomcompagni

The grinding process consists of reducing and standardizing the particle size of raw materials, increasing the contact surface, and consequently improving steam and water absorption during the extrusion process, favoring dough cooking. All these aspects affect the texture and uniformity, avoiding partially cooked hard particles in the product. Granulometry is influenced by the configuration of the mill and the parts that compose it. Before entering the mill, the presence of sieves and magnets will prevent foreign materials from reaching equipment, damaging parts, and impairing grinding quality. At the mill exit, to ensure the grinding quality, it is necessary to monitor the granulometry, which can be affected by perforated sieves or worn hammers, which will contribute to lower grinding efficiency and quality. Better steam and water absorption in extrusion, as a result of quality grinding, improves the efficiency of starch gelatinization, the process of transforming granular starch into a viscoelastic paste. Quality grinding and cooking allow better kibble expansion, formation, and structure. In general, product expansion is directly related to texture, being the products with the highest expansion, the most crunchy ones. Some of the parameters used to assess the degree of cooking of dietary ingredients that are subjected to extrusion are density and water absorption rate. Foods with high density and low water absorption are signs of poorly expanded products, with inadequate starch gelatinization and less nutrient utilization (Camire, 2000). The density of the expanded products is an important characteristic because, even indirectly, in addition to the expansion index, it indicates the degree of transformation of the starch granule. In the drying process, heat transfer is responsible for liquid evaporation, present in the food, and mass transfer by water movement from the food interior to its surface, and from there to the environment. Therefore, drying is linked to both environmental and intrinsic conditions of the material being dried, which influence evaporation and water molecules diffusion rates, respectively. Therefore, a kibble with good expansion and a uniform structure allows air to pass through it evenly, drying it properly, unlike a product that was compacted because it did not have an adequate process. Even the kibble expansion and structure, also interfere with the process of applying the liquid. The croquettes must have the capacity to absorb fat since their efficiency depends on the size and porosity of the extrudate. A well-extruded product with a good structure provides better penetration and retention of the liquid coating. Cereals (rice, corn, and wheat) are the most widely used starch sources in extruded dry food for dogs and cats. Some studies have shown that, if correctly extruded, cereal starch has an apparent digestibility greater than 95% for cats (DE OLIVEIRA et al., 2008) and 98% for dogs (CARCIOFI et al., 2008). However, starch digestibility can be affected by factors such as starch composition and physical form, protein-starch interactions, cell integrity, and the physical form of the feed. BAZZOLI (2007) evaluated the influence of milling of rice, corn, and sorghum on the apparent digestibility coefficient (ADC) of nutrients and fecal score in diets for dogs and found that there was a difference and interaction between carbohydrate sources in different millings. Mean starch and non-extractive nitrogen (ENN) ADCs were similar for the maize and sorghum diets, and higher for the rice-based diet. For maize and sorghum, coarse grinding had a negative effect, with values ​​lower than those of diets prepared with fine and medium grinding. Still according to BAZZOLLI (2007), regarding the fecal score, there was no ingredient effect either, only grinding. The evaluation of the contrasts shows that the higher the granulometry, the worse the fecal score for the three starch sources, and the worst score, being obtained with milled rice in a coarse granulometry. The evidence shows that the higher the granulometry, the worse the fecal score of the diets, a fact that is probably due to the decrease in the starch gelatinization index, which results in less dry matter in the feces and a worse score. In cats, KIENZLE (1993) found that the ADC of starch in a diet containing coarsely ground raw corn was 72%. When the corn was cooked or finely ground, the ADC of the starch was 100%. Starch digestibility alters and largely determines the postprandial blood glucose wave and the insulin response of the animal. In this way, the faster and more complete the digestion, the faster and more intense the triggered curve. This is an aspect that must be taken care of when thinking about food for animals with diabetes mellitus, obesity, pregnancy, cancer, and advanced age, which need greater control of the glycemic curve. Therefore, we conclude that grinding is a key point in high-quality product development. It must be standardized, according to the reality of each factory, in addition to taking into account product purpose and life stage or state of health of the pet that will consume the food.   Authors: Luana Pucca, Ludmila Barbi y Erika Stasieniuk Source: All Pet Food Magazine

23/12/2022

CPM Never Stops Evolving: New Colors Coming for CPM equipment

"The color change represents a step toward unifying our brand across the globe," said Maarten Visser, General Manager of CPM Americas/EMEA. "As CPM grows, our brand must evolve with it. We want our customers worldwide to associate the CPM name with the highest quality processing equipment available anywhere." "The new glossy white, accented with shiny black-gray, gives the equipment a sleek and modern new look. What's inside, Visser said, will not change at all". All types of CPM equipment are included in the upcoming color change, but existing orders will not be impacted. Equipment with the colors will be in the market later this year.   About CPM - History   The origin of CPM can be traced back to California's Napa Valley, where, in 1883, the Toulouse & Delorieux Co. manufactured presses, crushers and stemmers for winemakers. In 1931, the company created the first pellet mill, the 30 HP Flat Bed with stationary flat die, and we became California Pellet Mill (CPM). In the years that followed, we created more pellet mill models with additional features. In the 1980s, we greatly expanded our product offerings through the creation of Roskamp Champion with the acquisition of the Roskamp Roller Mill Company and Champion Hammermills. In 2002, Beta Raven, a leading supplier of feed mill automation and ingredient scaling systems, joined the team. To learn more about CPM products, click HERE. Source: CPM

02/02/2022

TOMRA food safety solutions for rendered meals, pet food products

All these food safety factors have a direct impact on the cost and payoff of raw materials — including commonly used pet food proteins like beef, poultry and rendered meals — and, subsequently, the reputation of brands. Strict food safety standards set by the Food Safety Modernization Act (FSMA) make it imperative for pet food brands and ingredient suppliers to safeguard their products; employing modern processing and food safety technologies is one way to go about this. To this end, TOMRA Food has highlighted which of its systems help produce safe rendered ingredients for pet food and finished pet food products. According to TOMRA, optical sorting offers renderers and pet food producers a leg up on conventional inspection methods, such as metal detection and x-ray systems. For example, the TOMRA 5C sorter can identify and reject foreign material in rendered meals before it reaches the pet food manufacturer. This 'final control' approach for rendered meals can also regulate ash content and enhance the final quality of a protein meal, the company said. For dry pet food manufacturing, the TOMRA Nimbus system can be used to identify foreign material and detect cross-contamination. The system's specific pet food software can store recipes, then use those set parameters to measure each piece of kibble and determine if it is a part of the right batch. The TOMRA 5B is best suited for pet treat and wet pet food processing. This system can prevent foreign materials from being included in final pet treat packaging, and also measures for consistent size, form and color of each treat. In wet pet food, the TOMRA 5B can be set up for in-bound ingredients to check for foreign materials in frozen protein ingredients. TOMRA suggests placing this system between the breaker or grinder and the mixer to prevent foreign materials from entering the mixer. The TOMRA 5B can identify stones, hard and soft plastics, metal, wood, glass, rubber and bone, and eject unwanted materials before the protein moves downstream. Aside from helping manufacturers meet rigorous food safety standards and protect their reputations, TOMRA noted its optical sorting equipment can also benefit sustainability and profitability for rendered protein suppliers and pet food manufacturers. The company's sorting solutions can protect value-added products from being wasted by identifying out-of-spec attributes further upstream, which protects the processor's investment in its ingredients, processes and environmental impact. 'Non-conformances with our customers have reduced dramatically, and we see very, very little waste or foreign bodies in our material,' said Craig Harrison, site manager for TOMRA. 'Our current customers have seen the difference in the finished product and there's lots of interest from additional customers enquiring about buying our material.' By Jordan Tyler - Pet Food Processing

13/12/2021

How can I grind more efficiently and with a smaller particle size standard deviation?

Series milling, in the simplest terms, is size reduction achieved in steps or stages. It usually incorporates two grinding machines: hammer mills and roller mills. The primary goal of step milling is to reduce the cost of producing one ton of finished ground product. Additional benefits may include better control of particle size distribution (more uniform grinding with fewer oversized and less fine particles), less heating of the product and subsequent loss of moisture, a reduction in maintenance cost per ton of ground material, potentially a finer finished product, and greater flexibility in the grinding circuit. Step milling process can employ two hammer mills, just one  hammer mill and a roller mill, or two roller mills. If you want to use a single machine, your step milling circuit will involve batch processing, that is, grinding a coarse batch, resetting the machine for finer particles, and processing again. Circulation grinding can be an alternative way to stagger grinding without the use of multiple equipment. You can use multiple sets of rollers in the roller mill, or a continuous operation of a roller mill or hammer mill with a screening stage to return oversized materials for reprocessing. Circulation grinding offers the potential to reduce energy and improve particle size control, but does not add more flexibility than the traditional two-machine grinding system. Step milling or traditional series milling also allows the flexibility to continue milling product while maintenance or part replacement is performed on the other equipment. A second approach, and one that is employed in various feed mills, is the use of two "series" mills, one that performs a pre-break / break and the second that achieves the desired particle size. Advantages of this type of circuit include lower grinding costs, finer finished products, a more uniform particle size, and a greater capacity of the total grinding system. The main disadvantage of this type of system is the higher capital / investment costs required to purchase and install. In most cases, the investment in the additional equipment pays off in 6 to 12 months with the energy savings of the grinding circuit alone. Additional benefits, such as increased life of wear parts, spare parts, and equipment life, are a huge plus in addition to such energy savings. If you want to further improve your energy efficiency and reduce operating costs, the recommendation is to screen between stages: removing larger materials before secondary milling or reprocessing these large materials to the initial equipment. Using two roller mills and one screen can allow you the flexibility to remove out-of-spec product and increase throughput between machines. The step milling approach produces this energy reduction, which means that less energy is required because the materials are reduced more gradually over a slightly longer period of time. By doing the same amount of work (grinding) over a longer period of time (two or three gradual grinds instead of an instant grind), the total power requirement is reduced. The roller mill offers significant energy savings compared to a hammer mill when processing material in the coarsest particle size ranges. With these characteristics, the use of the roller mill as a pre-breaking or pre-breaking device can offer substantial savings in a typical grinding circuit. This combination of finer feed and higher hammer mill efficiency not only reduces energy cost when grinding, but also reduces other operating costs, including maintenance and parts. In some cases, existing hammermills require increased capacity; the addition of a roller mill can increase the hammer mill capacity by as much as 40 to 50%, without changing the average particle size of the grind.   Source: CPM

27/10/2021

Why Only Remove Foreign Material from Dry Kibbles when you can also prevent Cross- Contamination

At best, the failure to separate different kinds of dry pet food products can cause buyers to doubt the manufacturer's quality controls and turn to a rival brand. At worst, a dog or cat with food allergies might be harmed by consuming a food-type not listed in the product's ingredients. The risk of cross-contamination is greatest when processing lines switch from one product batch or recipe to another. For this reason, some processors take the precaution of dumping the remnants of one kibble batch before switching to the next. Others simply hope for the best, thinking there's nothing much they can do about this. Neither approach is ideal, of course. For one thing, the habit of regularly discarding kibbles, sometimes in great quantities, is a costly waste of saleable stock. For another, the fast-spreading premiumization of the pet food market means that shoppers are becoming less willing to accept products which are visibly imperfect. And for another, something can now be done about this. In fact, everything can be done about this: in the last couple of years, TOMRA Food, the world-leading manufacturer of optical sorting machines, has introduced to the pet food industry a new and totally effective solution to the problem of cross-contamination. This solution is Biometric Signature Identification (BSI) technology, originally designed and developed to ensure the safety and quality of foods for human consumption. TOMRA's BSI+ scanner is uniquely capable of 'seeing' the biometric characteristics of all objects in the product stream, enabling the sorting machine to detect and eject unwanted materials even if they are identical to acceptable kibbles in size, shape, and color. This means it is now possible to prevent every single piece of unwanted kibble from getting to the end of the processing line. The BSI+ scanner's sorting platform is also capable of detecting and ejecting foreign materials from the product stream. This is essential, because the biscuits residue used as an ingredient in dry kibble can too easily be mixed-up with fragments of plastic or cardboard from wrappers and boxes. And it doesn't matter whether it's cross-contaminated product or foreign material - if a pet food buyer finds either in their bag of kibble, they're likely to switch to another brand. So now it's possible to guard against both threats, foreign material and cross-contamination - and without having to throw away saleable product Written by Lars Povlsen - Sales Manager Petfood Source: All Pet Food