High amylose pasta, more than an ideotype

by Michael Gusko Innovation Director (Goodmills Group), Silvia Folloni and Roberto Ranieri Open Fields

While much innovation in recent years has come from whole grain or pulses, certain wheat varieties now offer specific benefits, too. Although high-amylose starches are not a recent innovation, their popularity has increased in recent years due to their unique functional properties and improved nutritional value in food applications.

While high-amylose maize, barley, and potato are commercially available, highamylose varieties of other major crops such as wheat have also been developed more recently and will be available commercially soon. The commercialization of high amylose wheat semolina will certainly open a new area of food formulations with increased resistant starch (RS) and fiber. This is because distinctive structural features of highamylose wheat means that they are not fully broken down in the small intestine, whereas regular starches are more rapidly digested. High-amylose wheat therefore provokes a lower glycemic response compared to normal starches. Resistant starch is therefore also considered as dietary fiber. Most diets still have low amounts of dietary fiber and people are struggling to meet the recommended daily intake of dietary fiber from our diet. This is mainly due to excessive consumption of processed foods as well as the lack of availability of an adequate source of high fiber ingredients.

The EU has authorized the following health claim for resistant starch: “Replacing digestible starches with resistant starch in a meal contributes to a reduction in the blood glucose rise after that meal”. The claim was authorized by Regulation (EU) 432/2012 (2012) following a positive opinion from EFSA in 2011. The claim may be used only for food in which digestible starch has been replaced by resistant starch so that the final content of resistant starch is at least 14% of total starch. Achieving 14% RS as of total starch is possible, pasta made from 100% high-amylose durum wheat reaches these values.

Non-digested starches in the small intestine - RS - pass to the colon where they behave like dietary fiber. Higher levels of fiber consumption are associated with a lower risk of several metabolic diseases such as cardiovascular diseases, type 2 diabetes, and colorectal and breast cancer.

SCFAs serve two important functions: they reduce the pH of the colon, making it unfavorable for the proliferation of “undesirable” bacteria, and provide an energy source for cells lining the colon and protect the mucous layer covering the cell lining. They improve the health of colon cells and inhibits the growth and proliferation of tumor cells.

In the colon, RS is fermented by colonic microorganisms and the end products of fermentation, such as short-chain fatty acids, are known to have numerous health benefits, including lowering the risk of colorectal cancer and increasing immune function. The colonic fermentation of resistant starch produces short-chain fatty acids (SCFAs) such as butyrate, acetate, and propionate. These

While the health benefits of dietary fiber are well documented, the “big question” is why we still aren’t eating enough. Alongside factors like the need for increased education, sensory and taste characteristics of fiberenriched products are often viewed as inferior. The wheat bran in wholegrain pasta increases the coarseness of the pasta. There is still a large population, including children, that does not like whole meal pasta and prefers regular pasta from refined durum wheat. These problems, however, can be overcome with RS. High-amylose wheat contains about 40 percent dietary fiber, of which about 30 percent is RS. The interesting aspect is that the resistant starch is located in the bright endosperm of the grain. This means that semolina made from high-amylose wheat is golden yellow and gives the same fine taste in pasta as pasta made from standard semolina. Pasta processors can easily add fiber in their formulations replacing standard semolina with minimum effect on sensory properties. As highamylose starches do not swell and absorb water as much as many other dietary fibers, they are processing friendly. In order to measure the influence of highamylose semolina wheat on the sensory properties of pasta, different semolina formulations were developed in which highamylose wheat was mixed with standard durum in 25% steps. The recipes are shown in Figure 1. The “al dente” property of a pasta is an important characteristic, especially in Italy. The pasta made from 100% high amylose achieved a peak value of 100 index points. Pasta made from standard durum achieved a value of 67. Pasta made from high-amylose semolina is also much more stable when

FIRMNESS depending on cooking time (3 time points): optimum cooking time, cooked, with values of 87 and 80 for 25% and 50% longer cooking times, respectively (Figure 2). Mixing standard semolina with high amylose durum seems to be a cost-effective way to increase the firmness of the pasta.

Already a proportion of 25% high amylose semolina gives an index value of 87 (Figure 2).

The high-amylose wheat pasta is less sticky because less starch escapes during cooking (Figure 3) The bulkiness of the high-amylose pasta is also much favorable (Figure 4).

The total score of the high amylose pasta reached a value of 98, a significantly higher score than the 69 points of the control

Sensory: STICKINESS depending on cooking time (3 time points): optimum cooking time, +25%, +50%

Sensory:

(3 time points): optimum cooking time, +25%, +50% pasta (see Figure 5). With the availability of high-amylose wheat semolina, processors can directly use these flours to formulate products with an elevated level of resistant starch, a dietary fiber. Thus, the processor has the opportunity to make both resistant starch and fiber claims. High-amylose wheat semolina-

based products have better nutritional functionality in terms of lowering the glycemic response as well as improved colonic health.

This will be a win-win situation for consumers and processors.

time points): optimum cooking time, +25%, +50%