Dietary fiber analysis of common pulses using AOAC 2011.25: Implications for human health

Authors: CHEN, YIRAN - Colorado State University; McGee, Rebecca; Vandemark, George; BRICK, MARK - Colorado State University; THOMPSON, HENRY - Colorado State University

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2016
Publication Date: 12/21/2016
Citation: Chen, Y., Mcgee, R.J., Vandemark, G.J., Brick, M., Thompson, H. 2016. Dietary fiber analysis of common pulses using AOAC 2011.25: Implications for human health. Nutrients. doi: 10.3390/nu8120829.

Interpretive Summary: Dietary fiber is an important non-nutritive component of food and is believed to have various benefits to human health. In many countries, such as the United States and Canada, the intake of dietary fiber is 50 to 70% below recommended levels in greater than 95% of the population. We recently advanced the concept that low dietary fiber intake could be partially accounted for by the infrequent or low consumption of pulse crops. As defined by FAO, pulses are grain legumes; the four most widely consumed pulse crops globally are chickpeas (Cicer arietinum L.), common beans (Phaseolus vulgaris L.), dry peas (Pisum sativum L.), and lentils (Lens culinaris L.). In many cultures, these pulse crops are food staples, i.e. they are eaten daily in large amounts and are both affordable and accessible to the population. While this continues to be true in many developing countries, in other countries such as the United States and Canada, pulse consumption has been displaced with animal products, oil seed legumes such as soy (protein isolate), and peanuts. Consequently, while the FAO recommends the consumption of cereal grains to pulses in a ratio of 2:1 (food servings), the current pattern of consumption globally is 8:1. Interestingly, it has been shown in both the United States and Canada that individuals whose consumption of pulses is high (highest quartile of dietary intake) meet recommended levels of dietary fiber intake in comparison to non pulse consumers who eat the same daily number of servings of cereal grains. The consensus definition of dietary fiber, adopted in 2009 by the Codex Committee on Nutrition and Foods for Special Dietary Uses, and acceptance of a method by which it can be reliably determined (AOAC 2011.25) has resolved a long standing barrier to the field of dietary fiber and human health. We now apply AOAC 2011.25 to the comparative analysis of pulse crops, since this information is not available in current nutrient databases. The fiber content of these pulse crops was evaluated in seed types used for commercial production. These pulse crops have 2 to 3 times more fiber per 100g edible portion than other dietary staples. Moreover, there is marked variation in fiber content among cultivars of the same crop. This vaiiability among commercially grown cultivars of each crop demonstrates why efforts to brand foods with varietal information could help the consumer make more informed choices while providing an opportunity for food producers to advertise this value added aspect of their product without the need to make any health claims.

Technical Abstract: Dietary fiber is an important non-nutritive component of food and is believed to have various benefits to human health. In many countries, such as the United States and Canada, the intake of dietary fiber is 50 to 70% below recommended levels in greater than 95% of the population. We recently advanced the concept that low dietary fiber intake could be partially accounted for by the infrequent or low consumption of pulse crops. As defined by FAO, pulses are grain legumes; the four most widely consumed pulse crops globally are chickpeas (Cicer arietinum L.), common beans (Phaseolus vulgaris L.), dry peas (Pisum sativum L.), and lentils (Lens culinaris L.). In many cultures, these pulse crops are food staples, i.e. they are eaten daily in large amounts and are both affordable and accessible to the population. While this continues to be true in many developing countries, in other countries such as the United States and Canada, pulse consumption has been displaced with animal products, oil seed legumes such as soy (protein isolate), and peanuts. Consequently, while the FAO recommends the consumption of cereal grains to pulses in a ratio of 2:1 (food servings), the current pattern of consumption globally is 8:1. Interestingly, it has been shown in both the United States and Canada that individuals whose consumption of pulses is high (highest quartile of dietary intake) meet recommended levels of dietary fiber intake in comparison to non pulse consumers who eat the same daily number of servings of cereal grains. The consensus definition of dietary fiber, adopted in 2009 by the Codex Committee on Nutrition and Foods for Special Dietary Uses, and acceptance of a method by which it can be reliably determined (AOAC 2011.25) has resolved a long standing barrier to the field of dietary fiber and human health. We now apply AOAC 2011.25 to the comparative analysis of pulse crops, since this information is not available in current nutrient databases. The fiber content of these pulse crops was evaluated in seed types used for commercial production. These pulse crops have 2 to 3 times more fiber per 100g edible portion than other dietary staples. Moreover, there is marked variation in fiber content among cultivars of the same crop. This vaiiability among commercially grown cultivars of each crop demonstrates why efforts to brand foods with varietal information could help the consumer make more informed choices while providing an opportunity for food producers to advertise this value added aspect of their product without the need to make any health claims.