Eleftherios Bonos

Functional properties of carotenoids originating from algae

Carotenoids are isoprenoid molecules which are synthesised de novo by photosynthetic plants, fungi and algae and are responsible for the orange, yellow and some red colours of various fruits and vegetables. Carotenoids are lipophilic compounds, some of which act as provitamins A. These compounds can be divided into xanthophylls and carotenes. Many macroalgae and microalgae are rich in carotenoids, where these compounds aid in the absorption of sunlight. Industrially, these carotenoids are used as food pigments (in dairy products, beverages, etc.), as feed additives, in cosmetics and in pharmaceuticals, especially nowadays when there is an increasing demand by consumers for natural products. Production of carotenoids from algae has many advantages compared to other sources; for example, their production is cheap, easy and environmentally friendly; their extraction is easier, with higher yields, and there is no lack of raw materials or limited seasonal variation. Recently, there has been considerable interest in dietary carotenoids with respect to their antioxidant properties and their ability to reduce the incidence of some chronic diseases where free radicals are involved. Possibly, carotenoids protect cells from oxidative stress by quenching singlet oxygen damage with various mechanisms. Therefore, carotenoids derived from algae could be a leading natural resource in the research for potential functional ingredients.

Microalgae: a novel ingredient in nutrition

Microalgae are known for centuries, but their commercial large-scale production started a few decades ago. They can be grown in open-culture systems such as lakes or highly controlled close-culture systems, have higher productivity than the traditional crops and can be grown in climatic conditions and regions where other crops cannot be grown, such as desert and coastal areas. The edible microalgae are the green algae (chlorophyta) and the cyanobacteria. Microalgae contain substances of high biological value, such as polyunsaturated fatty acids, proteins, amino acids, pigments, antioxidants, vitamins and minerals. They are promising sources for novel products and applications and they can be used in the diet of humans and animals as natural foods with health benefits. Moreover, they can find use in the protection of the environment, as well as in pharmaceuticals, biofuel production and cosmetics.

Lactic Acid Bacteria as Source of Functional Ingredients

Lactic acid bacteria (LAB) are widespread microorganisms which can be found in any environment rich mainly in carbohydrates, such as plants, fermented foods and the mucosal surfaces of humans, terrestrial and marine animals. In the human and animal bodies, LAB are part of the normal microbiota or microflora, the ecosystem that naturally inhabits the gastrointestinal and genitourinary tracts, which is comprised by a large number of different bacterial species with a diverse amount of strains [1,2].

Essential Oils and their Applications in Animal Nutrition

Plant essential oils (EOs) and their compounds have proven in vitro efficacy as antimicrobial, antioxidant, immunodulating and anti-inflammatory agents. These substances deserve an important place as feed additives that are generally considered as safe. The available in vivo data show that EOs could find use as natural growth promoters in animal diets. However, the available evidence on the possible positive effects of these substances on nutrient digestibility and the function of the gut is rather limited. Also, the benefits of EOs’ applications in animal’s diets depend on diverse parameters. These parameters can be, on the one hand, the unstable composition and the different levels of addition in the diet, and on the other hand, variable animal genetic factors. A better understanding of the gastrointestinal tract microflora composition and activity is needed in order to maximize the use of EOs and to manufacture effective products. Essential oils could find application in cases where approved drugs or chemical substances are unwanted, for example, biological farming.

Innovative Microalgae Pigments as Functional Ingredients in Nutrition

Abstract Pigments derived from microalgae are promising natural sources of high-value compounds. These pigments, which include carotenoids, chlorophylls, and phycobiliproteins, have health-promoting properties such as vitamin precursors, antioxidants, immune enhancers, and anti-inflammatory agents. Accordingly, microalgae pigments can find commercial applications as innovative functional ingredients in the food and feed industries, as well as in pharmaceuticals and cosmetics. Nowadays, consumers are becoming increasingly aware of the correlation between diet, health, and disease prevention; as a result, they prefer these natural substances over synthesized ingredients. Nevertheless, some bottlenecks, such as high production costs and low yields, need to be solved before microalgae pigments can move from niche markets to large-scale use.

The influence of dietary Ascophyllum nodosum on haematologic parameters of dairy cows

The aim of the study was to investigate the effect of Ascophyllum nodosum, an edible brown macroalga, on some haematologic parameters of dairy cows. Nineteen clinically healthy Holstein cows, an average 4.3 years old, were divided into two groups for 49 days. Ten cows received control diet (roughages and concentrate) while the concentrate of 9 cows was additionally supplemented with 80 g A. nodosum/cow/day. Average daily milk production (controls 39.6 kg/cow; A. nodosum 40.2 kg/cow), milk protein and fat were not affected by the alga supplementation. Glucose, sorbitol dehydrogenase, haemoglobin, haematocrit and white/red blood cells were evaluated in weekly blood samples. It was seen that A. nodosum increased blood glucose and decreased sorbitol dehydrogenase compared to controls, without any adverse effects on the other examined parameters. Consequently, A. nodosum may be suggested as a functional ingredient in dairy cow nutrition, improving energy utilization and expressing hepatoprotective effect.

Comparative evaluation of dietary oregano, anise and olive leaves in laying Japanese quails

Aim of the present study was the comparative evaluation of the effect of ground oregano, anise and olive leaves as feed additives on performance and some egg quality characteristics of laying Japanese quails. A total of 189 Coturnix japonica quails (126 females and 63 males), 149 days old, were randomly allocated into seven equal groups with three subgroups of 9 birds each (6 females and 3 males). A commercial laying diet was fed to the control group. The remaining six groups were fed the same diet supplemented with oregano at 10 g/kg or 20 g/kg, anise at 10 g/kg or 20 g/kg and olive leaves at 10 g/kg or at 20 g/kg. The birds were offered feed and water ad libitum for a period of 29 days, while being kept under commercial conditions. During the experiment, egg production, feed intake and mortality were recorded daily. At the end of the feeding period egg weight, egg yolk, albumen and eggshell weight percentages, egg yolk color (using the L*a*b* color space) and blood serum triglycerides were determined. The diets supplemented with olive leaves (10 g/kg or 20 g/kg) resulted in a tendency (p = 0.054) for higher egg production percentage. Also, the color parameter a* was significantly (p = 0.001) higher in the eggs of quails that consumed oregano (10g/kg or 20 g/kg) or olive leaves (10g/kg or 20 g/kg).

The influence of mannan oligosaccharides, acidifiers and their combination on caecal microflora of Japanese quail (Coturnix japonica).

The aim of this study was to investigate the effects of the dietary supplementation of mannan oligosaccharides (MOS) extracted from yeast Saccharomyces cerevisiae, acidifiers-calcium formate (CF), calcium propionate (CP)- and their combination on the caecal microflora of Japanese quail (Coturnix japonica). Four hundred and fifty 1-day old quail where divided in six groups with three replicates each. One group that served as control received the basal diet. The five experimental diets consisted of the basal diet to which either 1 g MOS/kg, or 6 g CF/kg, or 6 g CP/kg, or 1 g MOS plus 6 g CF/kg or 1 g MOS plus 6 g CP/kg were added. The body weight was examined at weekly intervals and mortality was recorded daily. At days 21 and 42 of age, the total count of aerobic bacteria, lactic acid bacteria, enterobacteriaceae and coliforms in the caecal content of one bird of each replicate was determined. Also, at day 42 of age, two birds of each replicate were slaughtered and their carcass weight was determined. The results showed that MOS significantly (P ≤ 0.050) increased the total aerobic plate and lactic acid bacteria counts on day 21. Furthermore, CP significantly (P ≤ 0.050) decreased the total aerobic plate and lactic acid bacteria counts compared to controls on day 21. Significant interaction between MOS and acidifiers was noticed on total aerobic plate count on day 21. No significant (P > 0.050) difference was found in the caecal microflora on day 42. Finally, no significant (P > 0.050) difference was noticed on mortality, body and carcass weight.

Dietary carob pods on growth performance and meat quality of fattening pigs.

In this experiment the effect of dietary carob pods in the growth performance of fattening pigs and their meat quality, including steak chemical composition and fatty acid profile, were examined. A total of 160 weaning piglets, 30 days old, were allocated into four equal groups with 4 subgroups of 5 female and 5 males each. The animals were fed with isocaloric and isonitrogenous diets, containing either 0 or 75 or 100 or 125 g of carob pods per kg of feed. At the end of the experiment, on the 180 day of age, carcass subcutaneous fat thickness, steak chemical composition and steak fatty acid profile were determined. The results of the experiment showed that the dietary addition of 75 or 100 g/kg carob pods increased body weight at slaughter and carcass weight. No significant effect was noticed on the other examined carcass parameters. Consequently, carob pods could be suggested as a potential feed for fattening pigs without any adverse effect on their meat quality.

Evaluation of Oregano and α-Tocopheryl Acetate on Laying Japanese Quail Diets

In this experiment 108 Coturnix japonica quail, 149 days old, were randomly allocated into four equal groups with three subgroups of 9 birds each (6 females and 3 males). A commercial laying diet was fed to the control group. The remaining three groups were fed the same diet supplemented with ground oregano at 10 g/kg or 20 g/kg or additional 300 mg α-tocopheryl acetate /kg. The birds were offered feed and water ad libitum for a period of 29 days, while being kept under commercial conditions. During the whole experiment, egg production, feed consumption and mortality were recorded daily. Also, at the end of the experiment the egg weight, the weight percentages of egg yolk, albumen and shell, the egg yolk colour (using the L*a*b* colour space) were determined. Moreover, blood serum total cholesterol and triglycerides were determined. The results showed that the α-tocopheryl acetate addition did not affect any of the examined parameters. In contrast, oregano at 10 g/kg increased the a* yolk colour parameter (redness) compared to control, but did not affect the other examined parameters.