The month of May, a great month for pets to get out and enjoy everything outdoors as spring brings on new and exciting smells and adventures. In this issue Prof Simon Davies has a nice review of an issue many of us have been through with our pets and it is cancer. He covers the topic discussing nutritional aspects which assist the pets to help improve life quality.
Omega 3 fatty acids, fruits and vegetables, weight control and probiotics all topics which improve the well-being of the pets during these times. His insightful columns bring out a point that the interactions of the different branches in petfood production advance products and processes. Nutritionists formulate either inside or outside the bounds of the equipment. Those that discuss what the equipment can do in ranges before formulating are inside the boundaries of existing possibilities. Others voice what they feel is needed and at a point these desires have and do result in equipment and process advancements to achieve the goals.
Prof Davies mention of fruits and vegetables, natural sources of vitamins and antioxidants, are most likely being used in petfoods now and surely the level of use could increase. Years ago, this would have been hard to do but as noted above equipment improved to meet the ever-changing performance requirements. Reviewing what the industry uses for the majority of petfood production, extrusion systems, it needs to be noted these systems have capabilities of adding fruits and vegetables in liquid form or also as dry ingredients. The idea of using fresh is appealing for marketing points but also in my opinion taste. Dry ingredients are already processed and in the case of high moisture products the moisture is removed mainly by heat. You cook these ingredients twice where only once if pumped in fresh into the extruder. The process would be to take the ingredient and liquify it so that it is pumpable. The modern system would have flow meters coupled with loss in weight for the dry portion of the ration to combine in the proper ratio. Using these ingredients over time and for predictability and process control the liquified materials must have an adjusted and even moisture content over time. Therefore, a system where moistures can be taken and adjusted before pumping into the process is used. Might be easier to arrange to receive as needed from a supplier individual products or mixtures of fruits and mixes of veggies. The lower the moisture in the ingredient the higher the possible addition rate. On a general sense extrusion is limited to about 32 to 35 percent maximum moisture and make a kibble. Also, in a general sense as extruders and preconditioners do vary, adding 30 percent level of 65 percent moisture fruit or vegetable slurry would add in the area of 19 percent moisture, including for the moisture in the dry ingredients you are up in the maximum area with a bit of room for steam and water addition for control. Add some meat and this would also need to be part of the 19 or 20 percent additions again due to moisture. Having stated all of this there are systems and processes where elevated levels of moisture can be uses in extrusion thus increasing the possibility of elevated meat, fruit and vegetable inclusion well above the approximately 20 percent inclusion rate.
Maike Rakebrandt of Leiber GmbH reports on Brewer’s Yeast in detail with discussion on an advanced, improved and enhanced version. It improves the gut health while increasing palatability and can be topically applied onto the product. Perfect every petfood plant has a coating system and usually can apply either liquids or dry powders with accuracy. These coating systems, much like modern extrusion system, are where products come together in a line and are combined continuously or by batch continuous methods. At production tonnage produced ranges of five or six tonnes per hour and above the cost of each ingredient is such that the advanced weighing/flow controls is usually easily justified for cost control if nothing else. Hit your minimums on the label but don’t go over greatly. Coating system designs include flow control by weight of the dry kibble and dry additives and flow meter control of the liquids added. Accuracy allows for great reduction in over dosing but also allows to achieve precise levels to be added.
Dell Williams of Cablevey Conveyors reviews the fact that maintaining conveyors over time instead of “fix after failure” is recommended. Specifically, the discussions cover cable style conveyors. However, it is noteworthy that all of the other style of conveyors in plants need the same considerations which can cover a full range of styles including drag conveyors, screw conveyors, vibratory style, pneumatic systems both positive and negative, bucket style elevators styles, conveyors in dryers and even the screws in the extruders are conveyors. All need attention and dependent on the conveyor the preventive maintenance will vary. Your supplier surely covered schedules of maintenance on the devices supplied. Computer systems can include an hour meter and programs based on hours for alerts on lubrication and maintenance schedules.
A side note on conveyors and current requirements for salmonella free petfoods considerations need to be addressed in critical areas. The non-processed side or ingredient preparation area would have a different set of access or ability to clean then in the processed area. The extrusion process pretty much, and you should validate, kills the required bacteria to meet standards. Possibilities to develop problems after extrusion can re-contaminate the product thus attention to conveyor design and access or developed cleaning systems to disinfect the system.
Post the extrusion die usually a belt conveyor or mainly a negative pneumatic system is used. Either case ability to clean is necessary. Conveyors would be a manual method while systems exist for pneumatic lines. An air heating system verifying a temperature is reached in the pneumatic line is a method used to clean and eliminate bacteria in these systems. Other conveyors should have access for cleaning and sanitation again following the manufacturers recommendations.
This Editorial was published in the May edition of International Petfood Magazine.
