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The morphology and physiology of plants grown in vitro are regulated by various environmental factors such as light, temperature, humidity and carbon dioxide. Light, in its various parameters such as spectral quality, photon flux and photoperiod, is an important factor among these and generally influences the overall growth and development of plants in vitro. Light sources commonly used for in vitro plant culture are fluorescent lamps, although some research and commercial laboratories also use sodium metal or incandescent metal halide lamps. The spectral of those lamps range from 350 to 750 nm and contain blend lights that differentially affect in vitro plant growth. Recently, light emitting diodes (LEDs) have been developed and are nowadays used as an alternative source of fluorescent light for the development of plants both in greenhouses and in vitro culture rooms. In order to test the influence of these two types of light during multiplication phase, a multiplicity experiment was carried out using two species: a chestnut hybrid (Castanea sativa x C. crenata), clone M2 and the prickled broom (Pterospartum tridentatum (L.) Willk.), Malcata ecotype. Two types of light were tested, "cool white" fluorescent light and LED light with blue and red colors. It was found that LED illumination exerted a significant positive effect on the differentiation of shoots in the case of prickled broom (5.6 instead of 4.9 split shoots under fluorescent light). In the parameters of shoot length, we found that this type of lighting favored the elongation in both species. Regarding the parameters of fresh and dry weight, LED lighting caused a greater effect on the chestnut than on prickled broom. Some physiological parameters (chlorophylls, carotenoids and proteins) were also analyzed and showed to be influenced by the type of light during the development of microplants.

The antioxidant activity of bee pollen (mainly composed by Cistus ladanifer pellets) was explored in the context of black pudding production. For this purpose, three black pudding formulations comprising varying antioxidant compounds (sodium ascorbate, bee pollen and bee pollen extract) were produced. Bee pollen was characterized according to the botanical origin, antioxidant activity, total phenol and flavonoid contents and phenolic profile. Black pudding was characterized by the microbiological safety, lipid oxidation, pH, water activity and humidity at 1, 10, 21, 30 and 37 days. Sensory acceptance was evaluated on the four first periods of storage. Salmonella spp., Escherichia coli and Listeria monocytogenes were absent in all samples. Small variations on humidity and pH were observed during the black pudding's storage. Regarding lipid oxidation, it increased, on average, from 1.36 mg to 2.11 mg malondialdehyde/kg meat. Differences among the three formulations were only significant on the first days of storage. The sensory assessment did not differ between products. This study suggests that bee pollen may be used as a natural antioxidant in meat products, yet a careful labelling is essential to alert allergic consumers.