It is enviable to develop an environment-friendly packaging material against petroleum-based polymers with enhanced functionality to satisfy sustainable development and to secure and extend the shelf life of food. In this work, biopolymer chitosan was mixed with montmorillonite (MMT K10) nanoclay and spirulina algae to produce a bio nanocomposite film with high strength and barrier properties. Spirulina and MMT K10 was initially incorporated into chitosan to fabricate the chitosan/MMT K10/spirulina bio nanocomposite and the intermolecular interactions between the chitosan, MMT K10 and spirulina was improved by the synergistic effect of covalent and hydrogen bonds. The surface colour and opacity of chitosan bio nanocomposite films were found to be increased by the inclusion of MMT K10 and spirulina. The bio nanocomposite films exhibited good solubility and swelling property. The chitosan bio nanocomposite film with 0.5 g of spirulina revealed the promising features such as high tensile strength of 46.3 MPa, low oxygen and watervapour transmission rate of 996.79 cc/(m2. day.atm) and 7.12 g/m2/day which was better than other various concentration of spirulina based films. Furthermore, the antimicrobial properties of bio nanocomposite films were determined by colony count method and the results suggested the films had excellent antimicrobial properties against both gram-positive and gram-negative microorganisms and the composite films showed the good biodegradable property. The fabricated chitosan-based MMT K10 and spirulina incorporated bio nanocomposite films could make valuable contributions in active food packaging applications due to its excellent properties.
Spirulina In Tamil Pdf Download
Spirulina species have a significant content of proteins, essential amino acids, vitamins, carotenoids, minerals, essential fatty acids, polysaccharides, glycolipids, etc. [22,23,24], and for this reason, they are commonly used as functional foods whose consumption benefits human health and improves physical and mental performance [18]. The WHO pointed out that spirulina is one of the most relevant superfoods on earth, and NASA uses it for space travel, thanks to the wide range of nutrients that a small amount can provide [25]. In fact, spirulina contains a high level of B vitamins, in particular vitamin B12, and minerals including iron, calcium, zinc, magnesium, manganese, and potassium [26]. In addition, some essential fatty acids, such as gamma-linolenic acid (GLA) are present. Its phytocomplex is instead rich in pigments, including chlorophyll, phycobilins such as phycocyanin, and allophycocyanin (Table 1) [22,27,28]. It is important to note that spirulina nutrients are readily absorbed by the body and quickly restore deficient nutritional status to physiological levels [27]. In particular, the high bioavailability of micronutrients allows their rapid distribution even in the nervous system. B vitamins, magnesium, and fatty acids easily reach the brain through specific carriers exerting beneficial neuronal effects [26,28]. Moreover, as for other phytoderivates [29,30], spirulina phytocomplex can also affect the brain through a first interaction with the intestinal microbiota. In fact, preliminary in vivo evidence currently shows a bidirectional interaction between spirulina and the gut microbiota. On the one hand, the microbiota can biotransform the spirulina phytocomplex into small bioactive molecules able to reach the blood and exert their beneficial functions; on the other hand, spirulina seems to modulate the microbiota diversity towards an increase in the relative abundance of protective bacteria (Figure 1) [31,32].
Putative absorption, metabolism, and distribution in the CNS of spirulina nutrients and phyto-derivatives. Spirulina microalgae contain a plethora of nutrient molecules and phyto-derivatives which, once taken orally, can follow different ways of absorption. In particular, most of the nutrients such as minerals, vitamins, and amino acids are rapidly absorbed through specific transporters present in the colon and duodenum although a small part can also be absorbed at the sublingual level and in the stomach. The phyto-derivatives, on the other hand, mainly undergo metabolism by phase 1 and 2 enzymes residing in the small intestine despite the majority of phytoderivates metabolism taking place in the duodenum by the intestinal microbiota that biotransforms the phyto-derivatives into small bioactive metabolites able to enter the bloodstream [31,32,33,34].
Recent in vivo studies demonstrate that oral administration of spirulina once daily for 24 consecutive days altered the diversity, structure, and composition of the colonic microbial community at the genus level, including the relative abundance of Clostridium XIVa, Desulfovibrio, Eubacterium, Barnesiella, and Bacteroides, highlighting a dose-related modulation of the intestinal microbiota and physiological states by spirulina, which can be considered as a potential source of prebiotics for beneficial health effects through interaction with the intestinal microbiota [32]. Yu et al. also demonstrated a microbiota-effect of Spirulina platensis on the relative amount of Proteobacteria and the Firmicutes/Bacteroidetes ratio in fecal samples from rats fed with HFD [35].
By maintaining microbial homeostasis by reducing Proteobacteria hyperproliferation, favoring short-chain fatty acids (SCFA) production and keeping an intestinal barrier integrity, spirulina allows to reduce systemic inflammatory responses which can affect the brain health. A recent study investigated the effects of different doses of phycocyanin, one of the most common pigments in spirulina, on the gut microbiota and gut barrier integrity in mice. The results highlighted an increase in the saccharolytic bacteria of the Lachnospiraceae and Ruminococcaceae families, which can produce butyric acid, and an increase in the Rikenellaceae family, which contains hydrogen-producing bacteria. Furthermore, phycocyanin treatment reduced intestinal permeability and increased intestinal barrier function [36].
The modulation of microbiota diversity is, thus, one of the potential mechanisms of action of spirulina. The impact of spirulina microalgae on the gut microbiota homeostasis should be deeply analyzed by further in vivo studies to understand its mechanism of action at the CNS.
In a randomized, double-blind, placebo-controlled study, the antioxidant capacity, immunomodulatory and lipid-lowering effects of spirulina administered at a dose of 8 g/day for 16 consecutive weeks in healthy elderly subjects were evaluated. In this study, a significant reduction in total plasma cholesterol levels, a significant increase in plasma interleukin IL-2 concentration and IL-6 concentration, and a significant increase in superoxide dismutase activity after supplementation were observed, demonstrating that spirulina has favorable effects on the lipid profile, on the immune system and the antioxidant capacity of elderly subjects, becoming a useful functional food [67].
Beneficial effects of spirulina have also been found on blood glucose, lipids, and blood pressure levels. In a randomized, double-blind, placebo-controlled study, patients with hypertension but free from other cardiovascular diseases, after 3 months of supplementation with 2.0 g Hawaiian spirulina, showed a significant reduction in systolic blood pressure and body mass index, and an improvement of endothelial function [71]. Similar results were also obtained in another study in which Spirulina platensis was administered at a dose of 1 g per day for 12 weeks. This study found a decrease in total cholesterol levels and an increase in the serum concentration of HDL cholesterol, helping to control and prevent obesity-related disorders [72].
Spirulina grows naturally in mineral-rich alkaline lakes which can be found on every continent, often near volcanoes. The largest concentrations of spirulina today can be found at Lake Texcoco in Mexico, around Lake Chad in Central Africa and along the Great Rift Valley in east Africa. Since its re-discovery in the 1960s, spirulina has been exhaustively and extensively tested by scientists around the world, and is found to be the most powerful and well-balanced source of nutrition available on the planet.
Spirulina is called a super food because its nutrient content is more potent than any other food. Many of the essential nutrients needed by our bodies are concentrated in spirulina. It is comprised of at least 60% all-vegetable protein, essential vitamins and phytonutrients such as the rare essential fatty acid GLA, sulfolipids, glycolipids and polysaccharides.
Already in the 1970s, Aurovilians Bob and Deborah Lawlor started a small scale algae farm in Auroville's Success community with a mixture of green algae, mostly chlorella and scenedesmus. In their attempts at growing spirulina, they found that after a few weeks indigenous varieties of the chlorella species outgrew and replaced the original strain.
Although their project was very basic and operated with simple means, it was one of the first experimental spirulina farms worldwide, and even now is considered to have been of great value. So much so, that it is mentioned in the books written by Ripley D. Fox (the spirulina pioneer for the last decades). Another Aurovilian, old-timer Jim De Vries, was experimenting with chlorella farming at La Ferme around 1978. Jim used to pump the water with chlorella onto the rooftops of the buildings around the ponds (where nowadays the Auroville Cheese unit is located).
In the beginning of the 1990s, the late Swiss Bonaventura Chanson founded Simplicity with the vision of starting a spirulina farm there. He collected a lot of info and did various laboratory scale experiments pertaining to spirulina production.
In order to produce 1 kg of spirulina very little water is needed (the only significant loss is through evaporation) and even brackish or alkaline water, unsuitable for agriculture, can be used. Growing spirulina also requires very little surface area of land, with the further advantage that the land can be marginal, unusable and non-fertile. Spirulina protein uses 1/3 of the amount of water needed to grow soybeans and only 1/50th of the water needed for beef protein. Spirulina protein needs 20 times less land than soybeans and 200 times less than is required for beef production. Spirulina can help in the struggle with global warming as it fixes carbon and produces oxygen. 2ff7e9595c