Raw vs Heated vegetables, fruits and mesquite flour

Casa de Mesquite is strongly supportive of consuming most vegetables and fruits raw. One of the main reasons for consuming fruits and vegetables raw is that some of the vitamins are destroyed or greatly reduced by heat. If fruits and vegetables are boiled often much of the soluble vitamins are lost in the water used to boil the vegetables. The Food and Agricultural Organization (FAO) of the United Nations has provided a very good summary of the daily requirements of vitamins, those that are destroyed by heat and those that are lost upon boiling.

Another very good reason for consuming members of broccoli/cabbage/collards/rappini vegetables (botanically the Crucifers or Brassica family) raw is that this plant family contains well documented anti-cancer compounds that are produced when the cells are broken (as in mastication) by an enzyme known as myrosinase. The myrosinase converts a class of chemicals in the Brassica family known as glucosinolates, that do not have anti cancer activity, to isothiocyanates that do have anti cancer activity. Two of the most well known isothiocyanates are glucoraphanin under intensive research by Dr Fahey at Johns Hopkins University and indole 3-carbinol under intensive research at by Drs. Firestone and Bjeldanes at the University of California Berkeley. Temperatures of 140°F for l0 minutes will deactivate the myrosinase (Van Eylen al., 2007), and if this occurs, the glucosinolates without anti-cancer activity will not be converted to the anti-cancer isothiocyanate compounds (However a low conversion efficiency occurs in the lower part of human intestines).

In contrast to the beneficial effects of eating most fruits and vegetables raw, and especially vegetables of the Brassica family, eating raw legume seeds can pose health hazards. This is because common annual legumes such as peas, beans, soybeans contain proteins in their seeds with strong anti nutritional properties. Fortunately by heating these legume seeds, the proteins are denatured and the anti-nutritional properties are avoided. Common anti-nutritional proteins are called trypsin inhibitors and phytohemagglutinins. Trypsin is an enzyme in the intestinal system that breaks proteins down into smaller pieces so they can be digested and absorbed as amino acids. The trypsin inhibitors prevent this enzyme from working. Phytohemagglutinins are proteins that cause agglutination of red blood cells.

According to the Wilkipedia encyclopedia, as few as 5 uncooked kidney beans (Phaseolus vulgaris) can cause severe nausea and diarrhea 3 hours after eating. The Food and Agricultural Organization of the United Nations has published a compendium "Amino Acid Content of Foods and Biological Data on Proteins" (FAO, 1970). This compendium reports values for the Protein Efficiency Ratio of proteins from various sources in mixtures with other food sources, with supplementation with limiting amino acids and before and after cooking. The Protein Efficiency Ratio (PER) is obtained by feeding rats a diet of 10% of the protein being examined and measuring the weight gain after 30 days. The maximum value of 4 is assigned to the hen's egg which has the best balance of amino acids for humans. To illustrate the importance of destroying these anti-nutritional factors by heating, the FAO compendium lists raw soybean flour as having a PER of 0.54 and heat processed soybean flour to have a PER of 2.39. Generally pressure cooking for 15 minutes destroys the anti nutritional factor and maximizes nutritional value.

There is evidence for these anti-nutritional factors in mesquite. For example, Pak et. al., (1977) were the first to report trypsin inhibitors and phytohemagglutinins in the seeds of a Prosopis from Chile (P. tamarugo). Harden and Zolfaghari (1988) reported trypsin inhibitors in the seeds of Texas mesquite although at quite low levels. Oliveira et al., (2002) isolated and characterized the trypsin inhibitor from Prosopis juliflora in Brazil with the objective of using this protein as a bioinsecticide defense against insects and pathogens for the protection of bean seeds.

Mesquite flour preparations that are made from grinding the entire pod without heat treatment will have intact anti-nutritional factors. If this flour is incorporated into products that will be baked or cooked, there will be no effect of the anti-nutritional factors. However if the entire flour is eaten raw, these anti-nutritional factors could result in nausea and diarrhea.

A sometimes overlooked benefit of heating products which have been harvested off the ground in other countries is the reduction of bacteria that could result in gastrointestinal issues. Casa de Mesquite mesquite pods are rinsed in lightly chlorinated water that greatly reduces this potential hazard. Nonetheless mesquite flour is not as safe, as cocoa powder for example, that has gone through many processes. Therefore Casa de Mesquite strongly recommends and as our label indicates: "Cooking/baking is highly recommended. If one chooses to eat the product raw, after moistening the flour, keep all ingredients cool (preferably at refrigeration temperature), and consume the finished product within 20 minutes of flour moistening."

The preparation method used for Casa de Mesquite mesquite bean flour eliminates the anti-nutritional factors in two important ways. First, the seeds and the leathery capsule surrounding the seeds are eliminated by a combination of milling and sieving steps. This is done to obtain the most flavorful and aromatic part of the pod, which is the pulpy portion between the seed and the outer portion of the pod. Second, the pods are heated at about 130°F for 4 hours to remove the water so the high sugar content pods can be ground to a fine flour.

Casa de Mesquite has carefully examined the scientific literature to provide you with the product with the greatest aroma and flavor while doing everything possible to eliminate potential health risks. We hope you enjoy your mesquite flour experience. For further questions, please send a message to our web site.

  • FAO (1970). Amino Acid content of foods and biological data on proteins. FAO Nutritional Studies No 24. Food and Agricultural Organization of the United Nations, Rome, 285 pp.
  • Harden, M.L., and R. Zolfaghari (1988). Nutritive composition of green and ripe pods of honey mesquite (Prosopis glandulosa, Fabaceae). Economic Botany, 42: 522-532.
  • Oliveira, A.S., Pereira, R. A., Lima, L, M., Morais, A.H.A., Melo, F.R., Franco, O. L., Bloch, C., Grossi-de-Sa, M.F., and M. P. Sales. (2002) Activity toward Bruchid Pest of a Kunitz-Type Inhibitor from Seeds of the Algaroba Tree (Prosopis juliflora D.C.) Pesticide Biochemistry and Physiology 72, 122–132
  • Pak, N. Araya, H., Villalon, R. and M. A. Tagle. (1977). Analytical study of Tamarugo (Prosopis tamarugo) an autochthonous Chilean feed. Journal Science Food Agriculture 28: 59-62.
  • Van Eylen, D.I., Hendrick, O. M., and Van Loey, A. (2007). Kinetics of the Stability of Broccoli (Brassica oleracea Cv.Italica) Myrosinase and Isothiocyanates in Broccoli Juice during Pressure/Temperature Treatments. Journal of Agricultural and Food Chemistry, 55, 2163-2170