Safe Nuts

Nuts and seeds can be a terrific nutrient-dense snack or addition to a meal, but like grains and legumes, they also contain substances (Oxalates, Phytates and Saponins) that interfere with the body’s ability to absorb nutrients. Soaking and/or sprouting reduces the levels of enzyme inhibitors. Nuts have traditionally been considered a microbiologically safe product because of their low moisture content (low water activity). However, there have been a number of documented food-borne illness outbreaks and recalls caused by Salmonella and Aflatoxins in nuts and nut products.

Only buy human grade nuts and ensue proper handling and storage as they are susceptible to Salmonella and Aflatoxins. Aflatoxin are a carcinogenic mycotoxins in food which is produced by the Aspergillus flavus fungus. This fungus can contaminate foods such as grain, nuts and legumes such as peanuts. Salmonella is a gram negative bacteria.

Moisture is the single most important parameter and prompt drying to safe levels is essential for control of toxigenic mould's and bacteria. Foreign matter and damaged seed should be removed. Provision of clean, dry, adequately cooled and ventilated storage is important and good sanitation and hygiene is essential to minimise mould/bacterial contamination during storage and processing.

Aflatoxin-producing members of Aspergillus are common and widespread in nature. They can contaminate grain/nuts before harvest or during storage. Aspergillus lives in soil, decaying vegetation, hay, and rancid grains and nuts. Crops which are frequently infected include:
  • Grains such as corn, sorghum, pearl millet, rice, and wheat
  • Oilseeds such as peanuts, soybeans, sunflower seeds, and cottonseeds
  • Spices such as chile peppers, black pepper, coriander, turmeric, ginger
  • Tree nuts including almonds, pistachios, walnuts, coconuts, and brazil nuts.
references: Control and removal of aflatoxin - Food Safety Watch - Anti-nutritional factors - Prevalence of Salmonella in Cashews, Hazelnuts, Macadamia Nuts, Pecans, Pine Nuts, and Walnuts in the United States - What is Salmonella

Human Grade (unsalted)

Almond (dry roasted/no shells) Almonds contain high levels of anti-nutrients
Brazil Nut (no shells)
Cashew (roasted)
Palm nut
Peanut (roasted/no shells)
Pili nut (Canarium ovatum)
Pine nut
Walnut (roasted/no shells)

Why soak nuts and seeds?

Raw nuts, and even more so raw seeds, have high levels of Oxalates and Phytates, that when eaten contribute to potential nutrient deficiencies and low mineral absorbtion. The phytates and enzyme inhibitors can be neutralized by soaking and low temperature dehydrating or sprouting. Soaking increases the bioavailability of important nutrients (notably the treasured B vitamins) and activates helpful enzymes that increase nutrient absorption. Traditional methods of soaking use salt and many believe salt is necessary for the deactivation of the antinutrients. I do not believe salt water plays a part in Phytase activation. Many cultures practice soaking nuts using seawater and the sun.

Sprouting takes this process a step further. Note that pecans, walnuts, pine nuts, brazil nuts, macadamias and pasteurised almonds will NOT sprout, but they still contain phytates and enzyme inhibitors that should be removed by soaking. Only make as many fresh, raw sprouted nuts or seeds as can be consumed in 2-3 days. Store them in a covered stainless sleet bowl or jar in the refrigerator as sprouting can introduce problems with moulds and bacteria if not done correctly.

How to Soak

Involves the complete submergence of grains in water for certain amount of time period which results in the activation of endogenous phytases. Soaking should be at temperature between 45 and 65 °C and pH value between 5 and 6.
  1. Place raw, unsalted, organic nuts/seeds into a medium sized bowl
  2. Cover with filtered water so that nuts are submerged (add vinegar to lower the ph if necessary)
  3. Allow to soak covered on the counter overnight. (No more than 4-6 hours for cashews, walnuts, peanuts, pistachios).
  4. Rinse nuts and spread out in single layer on a rack to dehydrate.
  5. Dry at a low temperature no higher than 150°F, in dehydrator or oven for 12-24 hours or until slightly crispy.
  6. More information on Sprouting