How to obtain a functional product that is also rich in beta-glucans
In the previous Professional Pasta issue, we have described what makes barley flour pasta functional. We have explained what beta-glucans are in details. Now we are going to describe the chemical characteristics and the amino acid content of barley flour to be used in “our” pasta. They are resumed in tables 1 and 2.
It can be said that, like oat, barley is high in lysine, the essential carbohydrate that cereals do not contain in high quantity – as it is well known. As far as lysine content in durum semolina, barley and oat definitely prevail. If compared to oat, barley contains more lysine if this comparison only concerns the protein fraction, and not the whole edible part. The amino acid profile of barley flour (and pasta obtained from DV-4 mix) shall be mentioned, since the amino acid composition (especially essential amino acids) is a condition I have always carefully analyzed in testing formulations and therefore, it is always present in all laboratory documents related to it (Table 3 and 4).
The most critical variable of barley flour “functional” quality concerns, however, the bioactive component that better characterizes DV-4 formulation: the effective availability of beta-glucans in barley flour. In fact, their availability is important and depends on several factors: the most significant is barley variety genotype and, for that genotype, seasonal weather conditions, the pedological conditions of the soil on which it was grown as well as the agricultural technique used. Beta-glucans can be found in the structural part of barley caryopsis (just like all the organisms that contain beta-glucans, from bacteria to fungi, from algae to plants. So, in our case, it means that they are in the caryopsis cortical part and bran (aleurone). However, even endosperm (the inner starchy part of seed) contains high quantities that are distributed in cell walls.
Even the technological treatment of barley has a variable impact on soluble fiber availability (beta-glucans), as well as on the quantities of all the other nutritional compounds.
Barley technological treatment essentially consists in the following processes:
- Hulled barley (whole-grain barley);
- Pearl barley;
- Extraction/concentration of beta-glucans.
To obtain pearl barley, barley is processed in a similar way to rice: even if it is almost always recommended in macrobiotic diets, pearl barley loses significant amounts of its more characteristic ingredients, in particular minerals (calcium, phosphorus, iron), vitamin B1 (thiamine) and B2 (riboflavin). The milling process of whole-grain barley (that is hulled from outer cuticle, i.e. inner glume) provides a better output in terms of nutrients and, if barley has previously been roasted, the resulting flour will contain even more beta-glucans.
Therefore, the selection of both flour and its supplier should take into account the technology with which flour has been produced; and, if possible, also the variety of processed barley and any information the supplier can put down in writing.