Since its "discovery" in the early 1980s, resistant starch has been slowly creeping toward mainstream recognition. And it just might be on the verge of that kind of breakout. Resistant starch is a unique form of carbohydrate that, in formulation, behaves like starch, but when it hits the digestive system, it acts like fiber. It is resistant to digestion (hence the name) and provides a wealth of health benefits – but only about half the caloric content of nonresistant starch.
Like a fiber, it helps lower cholesterol, reduce cancer of the digestive system and protect against cardiovascular disease. Resistant starch is especially beneficial in helping manage diabetes and its precursor, insulin resistance. It does this by regulating blood sugar as well as dietary caloric intake through its propensity to increase satiety of a meal.
While resistant starch is a natural component found in bananas, parsnips, plantains, potatoes, yams and most legumes like beans, peas and lentils (but not soy), it also is in grains, especially barley, rice and high-amylose corn. It is in three natural forms, RS1, RS2 and RS3. Each form has to do with the structure and function of the starch molecule. As with other starches, resistant starch consists of a long chain of chemically bonded glucose molecules. But with resistant starch, they "clump" and thus keep the enzymes that digest it at bay.
Like fiber, resistant starch increases bulk and transit time through the gastrointestinal tract, resulting in less caloric absorption. It also reduces damaging impact on the cells lining the colon, helping avoid the type of alteration which leads to cancer cell formation.
- Resistant Starch 101: A Guide to Understanding This Fiber-Like Starch
- New Sources of Resistant Starch
But resistant starch also ends up in fermentation when it passes through the colon. In doing so, it acts as a powerful prebiotic. In turn, the beneficial gut bacteria it feeds increase digestive health and compete with harmful bacteria. The action of fermentation of resistant starch also stimulates the production by these probiotic gut bacteria of butyrate, an important short-chain fatty acid.
Butyrate has been shown in studies to lower the incidence of colon and rectal cancer. Beyond that, studies have shown butyrate actually favorably alters expression of genetic markers related to cancer, curtailing the growth of abnormal cells. Another fermentation byproduct, acetate, ends up burned as energy in muscle and fat cells.
Resistant starch has been shown in multiple research studies to lower both the glycemic and the insulin responses while encouraging a maintained release of energy. This is one way it reduces hunger and increases satiety. The fiberlike increase in bulk lends a feeling of fullness, and resulting slower absorption of glucose provides more even energy. And, research shows resistant starch alters the biochemical pathways of insulin, grehlin and leptin. These three are considered the main "hunger hormones." Resistant starch also raises the amount of glucagon-like peptide and PeptideYY, which slows gastric emptying. The two hormones are involved in communicating satiety from the gut to the brain.
Studies have demonstrated that 25-30g of resistant starch daily reverses insulin resistance, even for people who have full-on type-2 diabetes. Also, resistant starch has been shown to actually aid the body in metabolism of fat, becoming, in essence, a fat-burning ingredient. Human studies showed up to one-fifth increase in fat oxidation with resistant starch.
National Starch, now a part of Ingredion, has been the leading evangelist of resistant starch. The company developed its Hi-maize brand of resistant starch from high-amylose corn. Since then, a number of other ingredient suppliers have developed resistant starch from such sources as wheat, potatoes, legumes, even tapioca.
Robots in the plant
The robot industry made its mark in the 1980s with hundred-unit installations in the auto industry that took difficult jobs (welding, heavy lifting) away from line workers with tireless efficiency. Few jobs in the food plant match that job description.
But there are some. Nowadays, many food and beverage plants have at least one robot. It's probably toiling at the end of the line, stacking boxes of product onto pallets. Some plants have one a few feet upstream helping to fill those boxes with product. And there's a growing belief that any time you can remove human hands from the process, you can increase food safety and worker safety.
Sanitary robotic assemblies suitable for a USDA washdown environment still need to be developed, and that work won't proceed without revenue assurances. "Companies can't spend $5 million for development and get one order," cautions Rick Tallian, segment manager-U.S. packaging robotics at ABB Inc., Auburn Hills, Mich.
Before joining ABB, Tallian was a systems integrator. He was involved in a seminal installation of SCARA (selective compliance assembly robotic arm) robots in 1987 in a Pepperidge Farm plant in Willard, Ohio. The main reason was ergonomic issues, which resulted in an OSHA fine for repetitive motion injuries incurred by workers feverishly stacking cookies into packages.
Return on robotic investment is becoming easier to figure. Those first SCARA robots at Pepperidge Farm ran 55 cycles a minute, but cycle speeds increased 50 percent over the next decade. An even faster, cheaper solution didn't appear until the late 1990s, recalls Tallian, when Delta pick-and-place robots capable of 190 cycles a minute became available. That kick-started the food industry's embrace of the technology, he says.
"We needed to know the end customer's focus and requirements; we needed a company like Pepperidge Farm to say, ‘We'll jump off the cliff with you' to develop the technology," Tallian asserts.
The next breakthrough could be bin-picking machines that leverage 3-D vision technology from the gaming industry. If those systems could assemble products like Lunchables while also eliminating the need for infeed conveyors and other components of fixed automation, they could shrink the payback time for a new breed of bot.
This article appeared in our October 2013 issue of Food Processing magazine
Managing Editor Kevin Higgins contributed to this article.