l-Phenylalanine Ammonia-Lyase Activity During Germination of Phaseolus vulgaris

Edible Plant Sprouts: Health Benefits, Trends, and Opportunities for Novel Exploration

The consumption of plant sprouts as part of human day-to-day diets is gradually increasing, and their health benefit is attracting interest across multiple disciplines. The purpose of this review was to (a) critically evaluate the phytochemicals in selected sprouts (alfalfa, buckwheat, broccoli, and red cabbage), (b) describe the health benefits of sprouts, (c) assess the recent advances in sprout production, (d) rigorously evaluate their safety, and (e) suggest directions that merit special consideration for further novel research on sprouts. Young shoots are characterized by high levels of health-benefitting phytochemicals. Their utility as functional ingredients have been extensively described. Tremendous advances in the production and safety of sprouts have been made over the recent past and numerous reports have appeared in mainstream scientific journals describing their nutritional and medicinal properties. However, subjects such as application of sprouted seed flours in processed products, utilizing sprouts as leads in the synthesis of nanoparticles, and assessing the dynamics of a relationship between sprouts and gut health require special attention for future clinical exploration. Sprouting is an effective strategy allowing manipulation of phytochemicals in seeds to improve their health benefits.

Changes in phenolic acid composition and associated enzyme activity in shoot and kernel fractions of brown rice during germination

Phenolic acid composition and activities of two associated enzymes such as PAL (phenylalanine ammonia-lyase) and CW-PRX (cell wall peroxidase) in brown rice (BR) were examined during a germination for 4 days. Shoot and kernel fractions of the germinated brown rice were separated, and soluble extracts and insoluble residues of the fractions were analyzed. In the shoot fraction, the PAL activity and soluble phenolic acid content reached to its maximum on the second day of atmospheric germination, and decreased thereafter. In contrast, the amount of insoluble phenolic acids and CW-PRX activity continuously increased during the germination for 4 days. Comparing the shoot fractions, the kernel fraction exhibited lower activities of PAL and CW-PRX, but showed an increase in total phenolic acid content during germination. Germination raised the antioxidant activity of brown rice, especially in the shoot fraction which contained more phenolic acids than the kernel fraction.

Bioactive components and functional properties of biologically activated cereal grains: A bibliographic review

Whole grains provide energy, nutrients, fibers, and bioactive compounds that may synergistically contribute to their protective effects. A wide range of these compounds is affected by germination. While some compounds, such as β-glucans are degraded, others, like antioxidants and total phenolics are increased by means of biological activation of grains. The water and oil absorption capacity as well as emulsion and foaming capacity of biologically activated grains are also improved. Application of biological activation of grains is of emerging interest, which may significantly enhance the nutritional, functional, and bioactive content of grains, as well as improve palatability of grain foods in a natural way. Therefore, biological activation of cereals can be a way to produce food grains enriched with health-promoting compounds and enhanced functional attributes.

Dynamic changes in the free and bound phenolic compounds and antioxidant activity of brown rice at different germination stages

Germinated brown rice is a good source of the phenolics associated with antioxidant effects. Germination significantly increased by 63.2% and 23.6% the total phenolic and flavonoid contents, respectively. The percentage contribution of bound phenolics to total was 42.3% before and decreased slightly to 37.6% after germination. The percentage contribution of bound flavonoids to total, 51.1%, was the same before and after germination. The change in the amounts of free and bound forms indicated that transformations could occur during the germination process. Six individual phenolics were detected by HPLC. The levels of ferulic, coumaric, syringic, and caffeic acid significantly increased. The ratio of bound ferric reducing antioxidant power to total was basically constant, while germination increased the ratio of bound oxygen radical absorbance capacity to total. This indicated that the increase of bound phenolics exerts beneficial health effects throughout the digestive tract after absorption and may reduce mutations.

Biomass in the manufacture of industrial products--the use of proteins and amino acids

The depletion in fossil feedstocks, increasing oil prices, and the ecological problems associated with CO₂ emissions are forcing the development of alternative resources for energy, transport fuels, and chemicals: the replacement of fossil resources with CO₂ neutral biomass. Allied with this, the conversion of crude oil products utilizes primary products (ethylene, etc.) and their conversion to either materials or (functional) chemicals with the aid of co-reagents such as ammonia and various process steps to introduce functionalities such as -NH₂ into the simple structures of the primary products. Conversely, many products found in biomass often contain functionalities. Therefore, it is attractive to exploit this to bypass the use, and preparation of, co-reagents as well as eliminating various process steps by utilizing suitable biomass-based precursors for the production of chemicals. It is the aim of this mini-review to describe the scope of the possibilities to generate current functionalized chemical materials using amino acids from biomass instead of fossil resources, thereby taking advantage of the biomass structure in a more efficient way than solely utilizing biomass for the production of fuels or electricity.

On the Mechanism of the Changes in Phenylalanine Ammonia-lyase Activity Induced by Ultraviolet and Blue Light in Gherkin Hypocotyls

Irradiation with ultraviolet light causes in the hypocotyl of dark-grown gherkin seedlings the partial conversion of trans-hydroxycinnamic acids to the cis-isomers. The trans-hydroxycinnamic acids inhibit the development of phenylalanine ammonia-lyase activity, and the transformation of these compounds to the much less inhibitory cis-isomers forms a ready explanation for the increase in phenylalanine ammonia-lyase activity in the hypocotyl of gherkin seedlings irradiated with ultraviolet light. Arguments are advanced that the increase in phenylalanine ammonia-lyase activity caused by irradiation with blue light is also (at least in part) initiated by trans-cis isomerisation of the hydroxycinnamic acids.

Distribution of phenylalanine ammonia-lyase in etiolated and far-red irradiated radish seedlings

In dark-grown Raphanus seedlings, most of the PAL activity is found in roots where it increases sigmoidally during organ development. In hypocotyls, the dark increase of enzyme activity is linear with time. In cotyledons and hooks, dark activity is very low and remains constant. After onset of continuous far-red irradiation, an activity increase is observed in all parts of the seedling. In cotyledons and hooks, the increase is followed by a decrease. This is comparable to light-induced PAL activity described in other materials. In roots and hypocotyls, the initial increase is not followed by a decrease. In dark-grown roots and hypocotyls PAL activity is correlated to fresh weight augmentation. In no part of the seedling could a correlation be found between light-induced PAL activity and anthocyanin formation.

Effects of inhibitors of RNA and protein synthesis on bean hypocotyl hook opening and their implications regarding phytochrome action

Inhibitors of protein and RNA synthesis (cycloheximide, puromycin, chloramphenicol, and actinomycin D), as well as Co(++), induce opening of the hypocotyl hook of bean seedlings during the early stage of the opening period both in the darkness and red light. The response is transitory, however, complete straightening of a hook can not be achieved in the presence of these agents. These agents abolish the response of hooks to red illumination. They also block the suppression of hook opening caused by IAA and ethylene. The response and sensitivity to GA are not affected by the inhibitors. Inhibitors of DNA synthesis (FUDR and mitomycin C) have no effect on hook opening. It appears that in this growth response RNA and protein synthesis are more immediately involved in ethylene action than they are in the cell elongation process or the action of GA thereon.The results indicate that phytochrome does not induce hook opening simply by activating genes whose products directly promote growth. It is suggested that the regulation of ethylene formation by light and auxins may be exerted by way of influences on tissue levels of phenolic inhibitors of ethylene biosynthesis.