Bioaccessibility of Some Essential Minerals in Three Selected Australian Pulse Varieties Using an In Vitro Gastrointestinal Digestion Model

Abstract

Australian produced pulse grains are exported worldwide, predominantly to developing countries where severe essential mineral deficiencies putatively subsist. An in vitro digestion model that simulates human gastric, intestinal and colonic digestion and fermentation, was used to examine the bioaccessibility of Fe, Mg, K, Ca, P, Zn, Mn, and Cu in commercially available cultivars of Australian field pea, lentil, and sweet lupin. The hull and dehulled seeds were prepared following a traditional cooking method, and quantities of bioaccessible minerals were assessed at each stage of in vitro digestion using ICP‐OES elemental analyses. Results revealed that dehulled field pea (100 g dry weight) had the highest bioaccessible quantity of Fe (2.44 ± 0.73 mg), K (717.10 ± 56.66 mg), P (272.88 ± 9.30 mg), Zn (1.72.028 ± 0.28 mg), and Cu (0.41 ± 0.02 mg). Dehulled lupin was the best source of Mg (138.62 ± 1.53 mg) and Mn (1.28 ± 0.0.06 mg), and lentil hull showed the greatest Ca bioaccessible quantity (116.33 ± 16.73 mg/100 g dry weight). Additionally, the fed state digestion (11.7 mg bile/mL sample) increased the bioaccessibility of all elements significantly (P < 0.05) compared to fasted (1.95 mg bile/mL sample), except for Zn and Mn in lupin and lentils. These results demonstrated that dehulled seeds possess higher mineral bioaccessibility on a percentage basis compared with hulls, and that the fed state of in vitro digestion generally improved the mineral solubility significantly (P < 0.05). Practical Application This research aimed to assess the prospective biological accessibility of various essential elements in three commercially available Australian pulses. Results of the study provided an insight into the contents of essential minerals in Australian pulses and illustrated the impact of traditional cooking of dehulled pulses on these minerals bioaccessibility. These findings will provide the consumers with information about some nutritional aspects of major Australian pulses.

Temporal Change in Iron Content of Vegetables and Legumes in Australia: A Scoping Review

“…Amongst Australian-grown lentils, red, green, and French varieties were identified and analysed between 1997 and 2016. The highest iron concentration was reported in 1997 at 65.5 mg/100 g (unspecified variety) [ 34 ] but ranged from 5.4 (French) [ 39 ], 5.6 (green) [ 39 ] and 9.1 (red) [ 39 ] and 5.5–9.0 mg/100 g (unspecified varieties) in the 2010s [ 46 , 47 ].…”

“…Dried green peas were analysed between 1977 and 2016 on four occasions, with the highest iron content reported in 1977 (7.8 mg/100 g) [ 20 ], followed by 5.3 mg/100 g in 1997 [ 34 ], and 5.7–5.9 mg/100 g in 2010s [ 39 , 46 ]. Other varieties of dried peas (yellow, pigeon, cow pea) were only analysed at a single time point.…”

“…The most common lupins consumed by humans, sweet lupin ( Lupinus angustifolius) and white lupin ( Lupinus albus ), were both analysed at multiple timepoints. The iron content of sweet lupin ranged from 6.0–19.6 mg/100 g in the 1970s [ 20 , 21 , 23 ], 5.2 mg/100 g in 1980s [ 32 ]; 4.6–6.9 mg/100 g in 1990s [ 33 , 34 ], to 2.7–5.4 mg/100 g in 2010s [ 40 , 43 , 46 ] and 2.8 mg/100 g in 2021 [ 51 ]. For white lupin, the iron content showed a decrease; from 5.0–11.4 mg/100 g in late 1970s [ 20 , 21 , 22 , 23 ], to 4.2–4.3 mg/100 g in 1980s [ 32 ], 2.7 mg/100 g in 1990s [ 34 ] and 2.5 mg/100 g in 2021 [ 51 ].…”

The role of legume peptides released during different digestion stages in modulating the bioaccessibility of exogenous iron and zinc: An in-vitro study

“…A two-step digestion system adapted from our previous work ( Zhang et al, 2018 ) was employed, with simulated gastric and intestinal fluids prepared per the original model. However, the current investigation employed separate endpoints at the end of gastric and intestinal digestion, respectively, to quantify the soluble elements by the end of each stage.…”

“…All samples were digested according to our previous work ( Zhang et al, 2018 ). In summary, 2 mL from each soluble fraction of the gastric or intestinal digest was transferred into a 50 mL polypropylene tube (227261, Greiner Bio-One GmbH, Frickenhausen, Germany) containing 2 mL of 70% HNO 3 and 0.5 mL of 30% H 2 O 2 .…”