3.1.2. Fenugreek

Fenugreek is a traditional medicinal plant found in many cultures around the world [64]. Its culinary uses include the use of seeds as a spice and fresh leaves or sprouts and microgreens, which have a mild but slightly bitter taste. The absolute contents of AGM (2 mg/kg), PUT (2 mg/kg), SPD (59 mg/kg), and SPM (11 mg/kg) were lower in ungreminated seeds (Figure 2b, Figure A3) than in lentil seeds (Figure 2a). They were in a similar range as in the literature [14], except for SPD, in which a higher amount was determined in current work. Sprouting led to a large increase in practically all polyamines. CAD was below the limit of detection in ungerminated seeds and accumulated to more than 3000 mg/kg DW during sprouting. Such high levels are unusual in food samples and are twice as high as the maximal levels found in some acid-cured cheeses [65] or fresh scallops [62]. Higher DW based values were only found in some fermented soybean sauces [66]. AGM (1006 mg/kg) and PUT (1079 mg/kg) levels were above 1000 mg/kg DW but PUT levels were still in the range of foods such as sauerkraut [67], aged cheeses and even freshly squeezed citrus juices, which are among the richest sources of polyamines in unfermented foods [40]. Little information has been published on the AGM content of foods, but levels above 1000 mg/kg DW are undoubtedly high, as higher levels are found only in some fermented soybean products [39]. Despite initially lower contents in seeds, SPM (240 mg/kg) and SPD (87 mg/kg) in fenugreek sprouts have accumulated to twice the levels found in lentil sprouts. The accumulation of SPM and SPD during germination has not been observed before [68], and the increases of PUT and CAD contents were much less pronounced. The reason for the observed differences could be either their biological origin or the growth regime or methodology. In the previous study, the samples were processed by freeze-drying, which may have influenced the profile of the polyamine content, as shown in Section 3.2. Due to the extremely high content of CAD

(3563 mg/kg), fenugreek sprouts cannot be considered as a healthy food, despite the high amounts of the nutritionally beneficial polyamines AGM, SPD, and SPM.

The composition of the polyamines in fenugreek microgreens has been improved in terms of nutritional value, as well as in lentils. The four-fold lower content of CAD (873 mg/kg) and an order of magnitude higher content of SPM (922 mg/kg) in microgreens were the most pronounced changes compared to sprouts. None of the foods listed in the published databases [38,40,62] showed similarly high levels of SPM on a DW basis as we found in fenugreek microgreens. The estimated average daily dietary intake of SPM for the USA population [63] is exceeded by the consumption of 90 g of fenugreek microgreens (based on FW).
