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The effects of ‘activating’ almonds on consumer acceptance and gastrointestinal tolerance

European Journal of Nutrition volume 57, pages 2771–2783 (2018)Cite this article

Abstract

Purpose

Recommendations to soak nuts prior to consumption to reduce phytate concentrations and improve gastrointestinal tolerance have received much attention in the popular press. This is despite no supporting scientific evidence for the practice. There is also a lack of information about how soaking nuts might affect consumer acceptability. This study primarily assessed the effects of soaking almonds on consumer acceptance and secondly assessed effects on gastrointestinal tolerance.

Methods

In this 8-week randomised crossover trial, 76 participants were allocated in balanced order to receive 30 g/day of four different preparations of almonds for 12 days: whole unsoaked, whole soaked, sliced unsoaked, and sliced soaked. Ratings of overall liking, desire to consume, and likelihood of future consumption, and severity of gastrointestinal symptoms were measured daily on visual analogue scales. The phytate concentrations were measured in all four nut types using high-performance liquid chromatography.

Results

Mean acceptance ratings of all nut types were above the neutral point indicating they were acceptable. However, sliced soaked almonds were rated significantly lower overall for all three acceptance scales compared to the other treatments (all P ≤ 0.003). The sliced unsoaked almonds were rated lower than both whole nut treatments (all P ≤ 0.006), while there were no significant differences between the two whole nut treatments (all P ≥ 0.511). Gastrointestinal symptoms were minimal, but flatulence was rated significantly higher for all time points combined for soaked whole nuts compared to unsoaked whole nuts (P = 0.005). Compared to the whole unsoaked nuts (mean [SD] 531 [9] mg/100 g), phytate concentration was higher for the whole soaked almonds (563 [38] mg/100 g, P = 0.016), with no evidence of a difference for the sliced soaked almonds (548 [27] mg/100 g, P = 0.197) and no difference between the soaked forms (P = 0.262).

Conclusions

This research supports previous results suggesting nuts, including different forms, are an acceptable food. They are also well tolerated gastrointestinally, but soaking does not improve gastrointestinal tolerance or acceptance as claimed in the lay literature.

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References

  1. Alasalvar C, Bolling BW (2015) Review of nut phytochemicals, fat-soluble bioactives, antioxidant components and health effects. Br J Nutr 113(Suppl 2):S68–S78

    Article  CAS  Google Scholar 

  2. Brufau G, Boatella J, Rafecas M (2006) Nuts: source of energy and macronutrients. Br J Nutr 96:S24–S28

    Article  CAS  Google Scholar 

  3. Ros E (2010) Health benefits of nut consumption. Nutrients 2:652–682

    Article  CAS  Google Scholar 

  4. Aune D, Keum N, Giovannucci E, Fadnes LT, Boffetta P, Greenwood DC, Tonstad S, Vatten LJ, Riboli E, Norat T (2016) Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies. BMC Med 14:207

    Article  Google Scholar 

  5. Grosso G, Yang J, Marventano S, Micek A, Galvano F, Kales S (2015) Nut consumption and all-cause, cardiovascular, and cancer mortality risk: a systematic review and meta-analysis of epidemiologic studies. Am J Clin Nutr 101:783–793

    Article  CAS  Google Scholar 

  6. Hshieh TT, Petrone AB, Gaziano JM, Djousse L (2015) Nut consumption and risk of mortality in the Physicians’ Health Study. Am J Clin Nutr 101:407–412

    Article  CAS  Google Scholar 

  7. Tey S, Brown R, Chisholm A (2012) Nuts and heart health. National Heart Foundation of New Zealand evidence-based position statement on the relationship of nuts to heart health Auckland. New Zealand National Heart Foundation of New Zealand, Auckland

    Google Scholar 

  8. Willett WC, Sacks F, Trichopoulou A, Drescher G, Ferro-Luzzi A, Helsing E, Trichopoulos D (1995) Mediterranean diet pyramid: a cultural model for healthy eating. Am J Clin Nutr 61:1402S–1406S

    Article  CAS  Google Scholar 

  9. Brown RC, Tey SL, Gray AR, Chisholm A, Smith C, Fleming E, Blakey C, Parnell W (2014) Patterns and predictors of nut consumption: results from the 2008/09 New Zealand Adult Nutrition Survey. Br J Nutr 112:2028–2040

    Article  CAS  Google Scholar 

  10. Jenab M, Sabate J, Slimani N, Ferrari P, Mazuir M, Casagrande C, Deharveng G, Tyonneland A, Olsen A, Overvad K, Boutron-Ruault M-C, Clavel-Chapelon F, Boeing H, Weikert C, Linseisen J, Rohrmann S, Trichopoulou A, Naska A, Palli D, Sacerdote C, Tumino R, Mattiello A, Pala V, Bueno-de-Mesquita HB, Ock MC, Peeters PH, Engeset D, Skeie G, Jakszyn P, Ardanaz E, Quiros JR, Chirlaque MD, Martinez C, Amiano P, Berglund G, Palmqvist R, van Guelpen B, Bingham S, Key T, Riboli E (2006) Consumption and portion sizes of tree nuts, peanuts and seeds in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts from 10 European countries. Br J Nutr 96:S12–S23

    Article  CAS  Google Scholar 

  11. O’Neil CE, Keast DR, Nicklas TA, Fulgoni VL (2012) Out-of-hand nut consumption is associated with improved nutrient intake and health risk markers in US children and adults: National Health and Nutrition Examination Survey 1999–2004. Nutr Res 32:185–194

    Article  Google Scholar 

  12. O’Neil CE, Nicklas TA, Fulgoni VL (2015) Tree nut consumption is associated with better nutrient adequacy and diet quality in adults: National Health and Nutrition Examination Survey 2005–2010. Nutrients 7:595–607

    Article  Google Scholar 

  13. Beard M (2014) How soaking nuts helped my digestion. http://www.thenourishinggourmet.com/2014/01/how-soaking-nuts-helped-my-digestion-learn-in-3-simple-steps.html. Accessed 23 Oct 2016

  14. Cottis H (2012) Is soaking nuts necessary & how to properly soak your organic raw nuts. https://wholelifestylenutrition.com/recipes/appetizers-snacks/is-soaking-nuts-necessary-how-to-properly-soak-your-organic-raw-nuts. Accessed 23 Oct 2016

  15. Miles L (2013) Roasting, soaking, sprouting, activating, or eating raw—a guide to eating nuts. http://treadingmyownpath.com/2013/08/26/roasting-soaking-sprouting-activating-or-eating-raw-a-guide-to-eating-nuts. Accessed 23 Oct 2016

  16. Tieman J (2014) Why you need to activate nuts and seeds—how to do it. http://realfoodforager.com/why-you-need-to-activate-nuts-and-seeds-how-to-do-it. Accessed 23 Oct 2016

  17. Harland B, Smikle-Williams S, Oberleas D (2004) High performance liquid chromatography analysis of phytate (IP6) in selected foods. J Food Compos Anal 17:227–233

    Article  CAS  Google Scholar 

  18. Venkatachalam M, Sathe SK (2006) Chemical composition of selected edible nut seeds. J Agric Food Chem 54:4705–4714

    Article  CAS  Google Scholar 

  19. Hurrell RF (2004) Phytic acid degradation as a means of improving iron absorption. Int J Vitam Nutr Res 74:445–452

    Article  CAS  Google Scholar 

  20. International Zinc Nutrition Consultative Group, Brown KH, Rivera JA, Bhutta Z, Gibson RS, King JC, Lonnerdal B, Ruel MT, Sandtrom B, Wasantwisut E, Hotz C (2004) International Zinc Nutrition Consultative Group (IZiNCG) technical document #1. Assessment of the risk of zinc deficiency in populations and options for its control. Food Nutr Bull 25:S99–S203

    Article  Google Scholar 

  21. Kumar V, Sinha AK, Makkar HPS, Becker K (2010) Dietary roles of phytate and phytase in human nutrition: a review. Food Chem 120:945–959

    Article  CAS  Google Scholar 

  22. Afify Ael M, El-Beltagi HS, El-Salam SM, Omran AA (2011) Bioavailability of iron, zinc, phytate and phytase activity during soaking and germination of white sorghum varieties. PLoS One 6:e25512

    Article  Google Scholar 

  23. Gupta RK, Gangoliya SS, Singh NK (2015) Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains. J Food Sci Technol 52:676–684

    Article  CAS  Google Scholar 

  24. Lestienne I, Icard-Verniere C, Mouquet C, Picq C, Treche S (2005) Effects of soaking whole cereal and legume seeds on iron, zinc and phytate contents. Food Chem 89:421–425

    Article  CAS  Google Scholar 

  25. Lestienne I, Mouquet-Rivier C, Icard-Verniere C, Rochette I, Treche S (2005) The effects of soaking of whole, dehulled and ground millet and soybean seeds on phytate degradation and Phy/Fe and Phy/Zn molar ratios. Int J Food Sci Technol 40:391–399

    Article  CAS  Google Scholar 

  26. Hotz C, Gibson RS (2001) Assessment of home-based processing methods to reduce the phytate content and phytate/zinc molar ratio of white maize (Zea mays). J Agric Food Chem 49:692–698

    Article  CAS  Google Scholar 

  27. Darmon N, Drewnowski A (2008) Does social class predict diet quality? Am J Clin Nutr 87:1107–1117

    Article  CAS  Google Scholar 

  28. Tey SL, Brown R, Chisholm A, Gray A, Williams S, Delahunty C (2011) Current guidelines for nut consumption are achievable and sustainable: a hazelnut intervention. Br J Nutr 105:1503–1511

    Article  CAS  Google Scholar 

  29. Tey SL, Brown RC, Gray AR, Chisholm AW, Delahunty CM (2012) Long-term consumption of high energy-dense snack foods on sensory-specific satiety and intake. Am J Clin Nutr 95:1038–1047

    Article  CAS  Google Scholar 

  30. Tey SL, Delahunty C, Gray A, Chisholm A, Brown RC (2015) Effects of regular consumption of different forms of almonds and hazelnuts on acceptance and blood lipids. Eur J Nutr 54:483–487

    Article  CAS  Google Scholar 

  31. Tey SL, Gray AR, Chisholm AW, Delahunty CM, Brown RC (2013) The dose of hazelnuts influences acceptance and diet quality but not inflammatory markers and body composition in overweight and obese individuals. J Nutr 143:1254–1262

    Article  CAS  Google Scholar 

  32. Tey SL, Robinson T, Davis H, Gray A, Chisholm A, Brown RC (2015) The effect of regular hazelnut consumption on cardiovascular risk factors and acceptance in Maori and European. J Nutr 2:39–53

    Google Scholar 

  33. Ryan P (2000) RALLOC: Stata module to design randomized controlled trials: Statistical Software Components s319901. Boston College Department of Economics, Boston

    Google Scholar 

  34. Almond Board of Australia (2015) What are activated almonds? http://www.australianalmonds.com.au/enjoy/activated_almonds. Accessed 23 March 2016

  35. Mack R (2013) Everything you need to know about activating nuts. http://www.movenourishbelieve.com/nourish/everything-you-need-to-know-about-activating-nuts. Accessed 23 March 2015

  36. Grossmann K (2014) That’s nuts! A complete guide to soaking nuts and seeds. http://blog.radiantlifecatalog.com/bid/69542/That-s-Nuts-A-Complete-Guide-to-Soaking-Nuts-and-Seedsa. Accessed 3 Sept

  37. Lehrfeld J (1989) High-performance liquid chromatography analysis of phytic acid on a pH-stable, macroporous polymer column. Cereal Chem 66:510–515

    CAS  Google Scholar 

  38. Bingham A, Hurling R, Stocks J (2005) Acquisition of liking for spinach products. Food Qual Prefer 16:461–469

    Article  Google Scholar 

  39. Russell K, Delahunty C (2004) The effect of viscosity and volume on pleasantness and satiating power of rice milk. Food Qual Prefer 15:743–750

    Article  Google Scholar 

  40. Sulmont-Rossé C, Chabanet C, Issanchou S, Köster EP (2008) Impact of the arousal potential of uncommon drinks on the repeated exposure effect. Food Qual Prefer 19:412–420

    Article  Google Scholar 

  41. Zandstra EH, Weegels MF, van Spronsen AA, Klerk M (2004) Scoring or boring? Predicting boredom through repeated in-home consumption. Food Qual Prefer 15:549–557

    Article  Google Scholar 

  42. Devi A, Chisholm A, Gray A, Tey SL, Williamson-Poutama D, Cameron SL, Brown RC (2016) Nut-enriched bread is an effective and acceptable vehicle to improve regular nut consumption. Eur J Nutr 55:2281–2293

    Article  CAS  Google Scholar 

  43. Tey SL, Brown R, Gray A, Chisholm A, Delahunty C (2011) Nuts improve diet quality compared to other energy-dense snacks while maintaining body weight. J Nutr Metab 2011:357350

    Article  Google Scholar 

  44. Tey SL, Robinson T, Gray AR, Chisholm AW, Brown RC (2017) Do dry roasting, lightly salting nuts affect their cardioprotective properties and acceptability? Eur J Nutr 56:1025–1036

    Article  CAS  Google Scholar 

  45. Dahl WJ, Hanifi A, Zello GA, Tyler RT (2014) Gastrointestinal tolerance to daily canned chickpea intake. Can J Diet Pract Res 75:218–221

    Article  Google Scholar 

  46. Fleming SE, O’Donnell AU, Perman JA (1985) Influence of frequent and long-term bean consumption on colonic function and fermentation. Am J Clin Nutr 41:909–918

    Article  CAS  Google Scholar 

  47. Winham DM, Hutchins AM (2011) Perceptions of flatulence from bean consumption among adults in 3 feeding studies. Nutr J 10:128

    Article  Google Scholar 

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Acknowledgements

The authors would like to thank the participants for their commitment and enthusiasm in participating in this study.

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Authors and Affiliations

  1. Department of Human Nutrition, University of Otago, PO Box 56, Dunedin, 9054, New Zealand

    Heidi Taylor, Kirsten Webster, Siew Ling Tey, Alex Chisholm, Karl Bailey, Shivani Kumari & Rachel C. Brown

  2. Department of Preventive and Social Medicine, University of Otago, PO Box 56, Dunedin, 9054, New Zealand

    Andrew R. Gray

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  1. Heidi Taylor
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  2. Kirsten Webster
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Correspondence to Rachel C. Brown.

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Taylor, H., Webster, K., Gray, A.R. et al. The effects of ‘activating’ almonds on consumer acceptance and gastrointestinal tolerance. Eur J Nutr 57, 2771–2783 (2018). https://doi.org/10.1007/s00394-017-1543-7

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  • DOI: https://doi.org/10.1007/s00394-017-1543-7

Keywords

  • Nuts
  • Almonds
  • Phytate
  • Soaking
  • Activating
  • Gastrointestinal tolerance
  • Consumer acceptance