Results

Achieved results

The major objective of the project was to assess the possibilities of using germinated legumes (pulse) in food matrices, for developing new, vegan, clean label food products. In order to achieve the major objective, the following activities were targeted:

-       Estimation of the impact of the germination, in different environmental conditions, on bioactive compound synthesis and nutritional value of pulses

-       Determining the technological properties of germinated pulse flours in model systems and in complex food matrices

-       Obtaining new functional products from germinated pulse flours

The proposed research started from a TRL3 level, which includes analytical studies and laboratory studies to physically validate the analytical predictions of separate elements of the technology. The effect of germination on enhancing the bioactive compounds of pulses has been already proved. It is known that germination and fermentation are among the most inexpensive techniques to improve nutritive and health quality of cereals and legumes. Scientific literature indicated that legume germination resulted in improved protein and starch digestibility. Also, it increases soluble protein content, tiamine and fibres, and improves mineral bioavailability. Nonetheless, germination results in reducing the content of anti-nutritive compounds such as phitic acid, tanins, lectins and protease inhibitors. Scientific literature states that germinated pulses can be used as desirable functional ingredients or natural antioxidants in new food formulations.

Nutritive value of vegetable products can also be improved through fermentation process, by correctly selecting microorganisms strains responsible for fermentation process. In this respect, it can be stated that the ability of exopolysaccharides (EPZ) generation is one of the main selection criterions, together with the ability to produce lactic acid, flavor compounds, and texture stability, as EPZ contribute to texture stabilization against syneresis. It is stated that EPZ have nutritional functionality, presenting prebiotic activity.

The research project aimed at obtaining a TRL4 level, namely to integrate two basic technological components and to establish the extent to which they will work together. In order to obtain the TRL4 level, the research team assessed the technological functionality of germinated pulses, namely chickpea, broad bean and lentil, and integrated the obtained bio-functional flours into a sustainable technology, such as to obtain a new functional food based on germinated pulse flour. The challenge of the proposed research is to determine the effect of germinated flour integration into a complex food matrix and the impact of the thermal treatment on biological compounds synthetized in the germinated seeds.

Chickpea (C), broad bean (B) and lentil (L) seeds were subjected to germination in different environmental conditions. Soaked legumes were exposed to pulsed light at different fluence values – 19.2 J/cm² and 43.2 J/cm², to ultrasound treatment – 15 min 130W/38KHz and stationary magnetic field – 1h, 50mT. Also, germination in total darkness and in daylight were performed.

Among the conventional techniques used for food processing, germination is one the few processes that ensures significant increase in nutritional value by increasing the bioavailability of nutrients, vitamins, biominerals and other biologically active substances. Germination lead to significant modification in proximal composition of pulse flour. The highest protein contents were determined for broad bean samples, whereas lentil and chickpea had similar protein contents. When compared to the controls (native seeds), it was observed that germination ensured the significant increase of the protein content in case of all studied samples. In case of broad bean protein content incresed from 29.9% to 36.2%. Also, the germination process improved protein solubility and digestibility. Seeds treated under static magnetic field and ultrasounds presented a similar antioxidant activity after germination, while those subjected to pulsed light showed the highest Total phenol content. Regardless of the applied treatment, germination determined the increase of B1 vitamin content in case of chickpea. Also, vitamin C was detected in germinated lentil and broad bean samples while it was absent in control samples. The applied treatments influenced also protein digestibility. In this respect, pulsed light treatment was the most efficient in enhancing the nutritional functionality of studied legumes. In particular, the highest digestibility was found in case of chickpea seeds.

In order to achieve the last objective of the project, developing of a new functional food product, three technologies of obtaining a new functional product based on germinated pulses were targeted:

(a) Obtaining of a spreadable product by isoelectric precipitation of proteins through lactic fermentation,

(b) Developing of a bakery product, using the sourdough technology by mixing wheat flour with germinated pulse flour in ratio of 70:30, and

(c) Developing of a fermented product similar to yoghurt, from germinated pulses.

The final decision - to concentrate all the efforts for developing a germinated legume-based fermented product was taken after discussing with industrial producers, taking into account the Romanian market requirements for vegan products.

The obtaining of vegetable products from legumes other than soy as to offer an alternative to dairy products encounters some technological problems, especially because of high starch content of pulses (native soy beans contains only approximately 1% starch), together with the specific bean flavor. Also, development of lactic acid bacteria require the presence of carbohydrates with low molecular mass. The majority of technological solutions referring to the obtaining of vegetable fermented products with lactic acid bacteria, propose soy or rice as raw materials. Technological solutions for legumes as lentils, chickpea or broadbean are rare. The proposed solution was the combination of biotechnological process of germination with fermentation of the resulted vegetable milk with exopolysaccharide producing acid lactic bacteria. The resulted product is a vegetable fermented yoghurt like product with improved nutritional quality, and improved sensorial properties, the bean flavor being absent.