Bioactive principles from Cordyceps sinensis: A potent food supplement – A review

Cordyceps sinensis (CS) is a well-known entamophagus fungus, naturally distributed in the Tibetan Plateau of Asia and Himalayas. Recently this synonym is transferred to Ophiocordyceps by both scientific and non-scientific communities. It is widely used as a tonic and medicinal food in traditional Chinese medicine (TCM), as it possess wonderful health benefits. To support its functional attributes, various investigations have been carried out to find out its adaptogenic, aphrodisiac, anti-oxidant, anti-aging, neuroprotective, nootropic, immunomodulatory, anti-cancer and hepatoprotective role. Its fruiting portion as well as the larvae possesses potent bio-active fractions and their composition almost found to be similar in both. The bioactive principles are nucleosides, exo-polysaccharides, sterols and, proteins, among others. Among nucleosides, adenosine and cordycepin are the major biochemical markers. Further, different types of solvent extracts and their mixtures exhibit wide range of pharmacological activities, while the water and methanol extracts with the richest sources of nucleosides and polysaccharides also show wide range of pharmacological activities. This review gives a panoramic view of potential health benefits of various classes of bio-active fractions along with the need for sustainable management of CS for human wellness.     

Ochratoxin A in liquorice products – a review

Liquorice is a herbal medicine produced mainly in China and Iran. This plant is suspected to contain ochratoxin A (OTA), a secondary metabolite produced by fungi. Although liquorice is not included in the daily dietary of humans, the high levels of OTA reported in this product have concerned consumers. Registration of a standard method for measuring the amount of this mycotoxin in liquorice-derived products is an important challenge and requires the introduction of a reliable, simple, fast-performance and reproducible technique. This review examines studies carried out concerning the occurrence of OTA in liquorice products. Recent information regarding contaminated liquorice, the regulatory framework and methods to degrade OTA in liquorice are discussed.     

Technical difficulties and future challenges in isolating membrane material from milk fat globules in industrial settings – A critical review

Research on the milk fat globule and surrounding membrane began a century ago. Synthesis and secretion mechanisms of milk fat globules in mammary epithelial cells are well documented, but there is still controversy about the composition of the milk fat globule membrane (MFGM). In recent years, interest in isolating MFGM material has increased because of the presumed functional potential of the proteins and lipids. However, no standardised isolation procedure exists to our knowledge. Consequently, published reports on the MFGM composition differ significantly. Various isolation methods under different conditions were applied, and contradictory effects on the MFGM structure were obtained. In addition to compositional changes, losses of MFGM material also occur under particular conditions. This makes it difficult to compare reports on the composition of the isolated MFGM material. We therefore saw a necessity to critically review past and current literature with emphasis on the reported isolation methods and respective results.     

Dietary fiber extraction for human nutrition—A review

Fiber is a mixture of nonstarch polysaccharides that resist digestion by enzymes in the gastrointestinal canal. Some known methods of extracting fiber from plant sources include dry processing, wet processing, chemical, gravimetric, enzymatic, physical, microbial, or a combination of these methods. Modified wet milling is the most cost-effective in the wet milling group, as it uses minimal chemicals, produces high purity products, and uses less water than the other methods. The purity of fibers extracted using the modified wet milling method range from 49.7% to 89.6%. An ideal extraction method should be affordable and produce fibers of high purity.     

Gelation of gellan – A review

Gellan is an anionic extracellular bacterial polysaccharide discovered in 1978. Acyl groups present in the native polymer are removed by alkaline hydrolysis in normal commercial production, giving the charged tetrasaccharide repeating sequence: → 3)-β-d-Glcp-(1 → 4)-β-d-GlcpA-(1 → 4)-β-d-Glcp-(1 → 4)-α-l-Rhap-(1 →. Deacylated gellan converts on cooling from disordered coils to 3-fold double helices. The coil–helix transition temperature (T_m) is raised by salt in the way expected from polyelectrolyte theory: equivalent molar concentrations of different monovalent cations (Group I and Me₄N⁺) cause the same increase in T_m; there is also no selectivity between different divalent (Group II) cations, but divalent cations cause greater elevation of T_m than monovalent. Cations present as counterions to the charged groups of the polymer have the same effect as those introduced by addition of salt. Increasing polymer concentration raises T_m because of the consequent increase in concentration of the counterions, but the concentration of polymer chains themselves does not affect T_m. Gelation occurs by aggregation of double helices. Aggregation stabilises the helices to temperatures higher than those at which they form on cooling, giving thermal hysteresis between gelation and melting. Melting of aggregated and non-aggregated helices can be seen as separate thermal and rheological processes. Reduction in pH promotes aggregation and gelation by decreasing the negative charge on the polymer and thus decreasing electrostatic repulsion between the helices. Group I cations decrease repulsion by binding to the helices in specific coordination sites around the carboxylate groups of the polymer. Strength of binding increases with increasing ionic size (Li⁺ < Na⁺ < K⁺ < Rb⁺ < Cs⁺); the extent of aggregation and effectiveness in promoting gel formation increase in the same order. Me₄N⁺ cations, which cannot form coordination complexes, act solely by non-specific screening of electrostatic repulsion, and give gels only at very high concentration (above ∼0.6 M). At low concentrations of monovalent cations, ordered gellan behaves like a normal polymer solution; as salt concentration is increased there is then a region where fluid “weak gels” are formed, before the cation concentration becomes sufficient to give true, self-supporting gels. Aggregation and consequent gelation with Group II cations occurs by direct site-binding of the divalent ions between gellan double helices. High concentrations of salt or acid cause excessive aggregation, with consequent reduction in gel strength. Maximum strength with divalent cations comes at about stoichiometric equivalence to the gellan carboxylate groups. Much higher concentrations of monovalent cations are required to attain maximum gel strength. The content of divalent cations in commercial gellan is normally sufficient to give cohesive gels at polymer concentrations down to ∼0.15 wt %. Gellan gels are very brittle, and have excellent flavour release. The networks are dynamic: gellan gels release polymer chains when immersed in water and show substantial recovery from mechanical disruption or expulsion of water by slow compression. High concentrations of sugar (∼70 wt % and above) inhibit aggregation and give sparingly-crosslinked networks which vitrify on cooling. Gellan forms coupled networks with konjac glucomannan and tamarind xyloglucan, phase-separated networks with kappa carrageenan and calcium alginate, interpenetrating networks with agarose and gelling maltodextrin, and complex coacervates with gelatin under acidic conditions. Native gellan carries acetyl and l-glyceryl groups at, respectively, O(6) and O(2) of the 3-linked glucose residue in the tetrasaccharide repeat unit. The presence of these substituents does not change the overall double helix structure, but has profound effects on gelation. l-Glyceryl groups stabilise the double helix by forming additional hydrogen bonds within and between the two strands, giving higher gelation temperatures, but abolish the binding site for metal ions by changing the orientation of the adjacent glucuronate residue and its carboxyl group. The consequent loss of cation-mediated aggregation reduces gel strength and brittleness, and eliminates thermal hysteresis. Aggregation is further inhibited by acetyl groups located on the periphery of the double helix. Gellan with a high content of residual acyl groups is available commercially as “high acyl gellan”. Mixtures of high acyl and deacylated gellan form interpenetrating networks, with no double helices incorporating strands of both types. Gellan has numerous existing and potential practical applications in food, cosmetics, toiletries, pharmaceuticals and microbiology.     

Processing of high-protein yoghurt – A review

High-protein yoghurt has gained increased consumer interest over the recent years, partly driven by improvements in taste and texture; there is also greater scientific evidence on dairy protein health benefits. The protein content of yoghurt can be increased prior to fermentation by addition of dairy powder, evaporation or membrane filtration, or after fermentation by straining, mechanical separation, or membrane filtration. Concentration of yoghurt after fermentation produces large volumes of acid whey, a major concern for the dairy industry; by concentrating prior to fermentation, production of acid whey is avoided. Different processing techniques influence yoghurt composition, structure, rheology, and sensory properties. This review discusses the challenges, opportunities, the influence of macro components in milk and different processing techniques on composition, structure, rheology, and sensory properties of high-protein yoghurt, along with their benefits and drawbacks for the dairy producer.     

Bacillus thermoamylovorans – A new threat to the dairy industry – A review

Bacillus thermoamylovorans is a newly described spore forming bacterium emerging in the dairy industry. There is an increasing threat of B. thermoamylovorans contamination, not only in food ingredients and raw milk, but also in sterilised milk and dairy products. Animal feed, processing equipment, and farm environments are potential entry points for contamination of milk with B. thermoamylovorans. The ability of B. thermoamylovorans to produce lipolytic and β-galactosidase enzymes is linked to food spoilage. B. thermoamylovorans spores have a heat resistance comparable with that of the spores of Bacillus sporothermodurans, indicating the potential to survive ultra-high temperature treatments. However, despite the rise in reports of the isolation of B. thermoamylovorans from dairy samples, there have been few reports on the characterisation of these bacteria. The origin, characteristics and potential issues resulting from B. thermoamylovorans in the dairy industry and potential methods of control are discussed in this review.     

X-ray-protective organic/inorganic fiber – along the textile chain from fiber production to clothing application

High X-ray absorption and, therefore, excellent X-ray protection properties are related to heavy chemical elements. Therefore, a composite fiber for X-ray protection applications was developed consisting of an organic cellulose part and an inorganic part. Whereas the preceding part provides the common properties connected to fibers and the latter part ensures the X-ray protection effect. The treatment of this composite fiber along the whole textile chain is presented and the possible usage as a common textile fiber in spinning and knitting processes is impressively demonstrated. Textile properties such as air permeability and abrasion stability are successfully tested. Furthermore, the microscopic structure is characterized by means of optical and scanning electron microscopy. The X-ray protective properties are determined by transmission experiments. The realization of a textile product is shown by production of a glove, where protective properties are impressively shown by 3D X-ray tomography. Altogether, the complete production process of X-ray protective textile products using organic/inorganic composite fibers is introduced. Immanent to the presented material are the broad opportunities for developing textile products for X-ray protective applications in medicine, security technology, or materials analytics.     

Exudate gums: chemistry,properties and food applications – a review

Gums are complex carbohydrate molecules which have the ability to bind water and form gels at low concentration. These carbohydrates are often associated with proteins and minerals in their structure. Gums are of various types such as seed gums, exudate gums, microbial gums, mucilage gums, seaweeds gums, etc. Exudate gums are plant gums which ooze out from bark as a result of a protection mechanism upon injury. Exudate gums have been used by humans since ancient times for various applications due to their easy availability. The main characteristics which make them fit for use in various applications are viscosity, adhesive property, stabilization effect, emulsification action and surface-active property. Major applications of these gums are in food products, the paper, textile, cosmetics and pharmaceutical industries, oil-well drilling, etc. In the present paper, the chemistry, properties, processing and applications of commercially available exudate gums such as acacia gum or gum arabic, karaya gum, ghatti gum and tragacanth gum are discussed. Recent literature reveals that apart from the above mentioned applications, these gums also have nutritional properties which are being explored. Other gums cannot replace them because of their certain unique characteristics. © 2020 Society of Chemical Industry     

Food drying enhancement by ultrasound – A review

BackgroundDrying is one of the most popular methods of preserving a wide variety of food and agricultural products. Unfortunately, this unit operation may negatively influence product quality. Moreover, due to the high heat capacity of water, drying is usually a long-lasting and energy-intensive process, thus new drying techniques are continuously being sought.Scope and approachThis review presents the current state of art in ultrasonic-assisted drying. Despite immense knowledge on the principles of ultrasound generation and action, this technology has found no practical application in industrial drying yet. In this paper we tried to find the reasons for this state of affairs. Up-to-date designs of dryers using ultrasound to enhance the drying process and the various possible mechanisms of accelerating the drying process with the application of ultrasonic waves are discussed. The influence of ultrasound on the product's quality (dried food) is judged and described.Key findings and conclusionsThe analysis of the results presented by the researchers here allows to state that applying ultrasound to drying caused a shortening of the drying time and could reduce total energy consumption. Moreover, due to the small “temperature effect”, the quality of the obtained products was noticeably better as compared to the control processes (without ultrasound enhancement). The lack of an effective technology for generating power ultrasound in air was distinguished as the primary constraint for industrial application of this technology. The necessity of conducting detailed studies on ultrasound application in drying was emphasized.     

Browning development in bakery products – A review

This paper presents a review regarding several aspects of the development of browning during baking of bakery products, mainly from an engineering point of view. During baking, the formation of colour is due to the Maillard reaction, and caramelization of sugars. Besides the major influence of this phenomenon on the initial acceptance of products by consumers, it is the responsible for other relevant changes occurring in food during baking, i.e. production of flavour and aroma compounds, formation of toxic products (e.g. acrylamide), and decrease of nutritional value of proteins. As well as baking, the development of browning in bakery products is a simultaneous heat and mass transfer process that occurs mostly in a non-ideal system under non-ideal conditions. In addition, the mechanisms of chemical reactions involved are still not elucidated completely, so the process is difficult to control and represents a major challenge for food engineers. Effects of browning on properties of products and experimental, modelling and technological aspects of colour formation during baking are reviewed.     

Fumonisins in plant-origin food and fodder – a review

Fumonisins are mycotoxins produced by the Fusarium group of fungi commonly found on crops, mainly on maize. Some data suggest that as much as 25% of world crops may be lost because of mycotoxin contamination. Therefore, researchers in many countries (particularly in those in which relatively large amounts of maize are directly consumed by humans) are concerned with fumonisin levels in plant-origin foodstuffs and feeds available in their local markets. There is no doubt the levels are strongly correlated with the climate conditions prevailing in the region in which the maize was cultivated: the hotter the climate, the more serious the problem. Negative consequences of consumption of fumonisin-contaminated food by humans include an increased risk of oesophagus cancer and decreased body mass growth. In recent years some trials have been undertaken to reduce fumonisin levels in food and feed by the application of isothiocyanates naturally occurring in plants or peptidoglycans isolated from lactic acid bacteria (LAB). The results of these studies suggested that some reduction in contamination levels might be achieved. Additionally, some recent studies indicate that Sphingopyxis sp. bacteria produce enzymes that are able to break down the fumonisin molecule. Some fumonisins present in food may be bound/coupled with other compounds, and therefore difficult to detect. Such complexes in which the toxins are masked or hidden may even be at higher levels than the not-bound (free) molecules. The problem of how to evaluate effectively and efficiently the concentration of fumonisins in various foodstuffs is therefore a real-life challenge for scientists.     

Hot towels: The bedrock of Meibomian gland dysfunction treatment – A review

BackgroundMeibomian gland dysfunction (MGD) reduces quality-of-life and hinders work productivity of millions of patients, with high direct and indirect societal costs. Thickened meibum obstructs the glands and disrupts ocular surface health. Heating the eyelids to soften and express meibum from the glands can be beneficial. The most accessible method for eyelid warming uses heated, wet towels. However, the efficacy of this treatment is reliant on the methodology, and evidence-based best-practice recommendations are needed.PurposeTo evaluate the literature on hot towels in MGD treatment and recommend a best-practice protocol for future research and patient treatment.MethodsStudies were identified through PubMed on the May 28, 2021, with the search terms: (warm* OR heat* OR thermal* OR towel OR wet towel) AND (meibomian OR MGD OR eyelid OR “dry eye” OR DED). All relevant original articles with English full-text were included.ResultsThe search yielded 903 results, of which 22 met the inclusion criteria. Across studies, hot towels were found to be effective at reducing ocular symptoms. However, without reheating, the temperature quickly fell below the therapeutic range, which was deemed to be between 40 °C and 47 °C. Towels heated to around 45 °C and reheated every-two minutes were most effective at increasing eyelid temperature, comparable or better than several commercially available eyelid warming devices. No adverse effects were reported in the studies.ConclusionHot towel treatment effectively warms the eyelids and reduces ocular symptoms, but must be standardized, and towels reheated to achieve maximum benefit. Future research should assess patient satisfaction with different hot towel treatment methods that reheat or replace the towel at least every-two minutes, to establish which methods yield the greatest compliance. Guidelines or clinical recommendations that do not mention the need for regular reheating during hot towel compress treatment should be updated to include this.     

Electrically-induced transport phenomena in EHD drying – A review

BackgroundElectrohydrodynamic (EHD) drying is non-thermal and energy efficient technology, which appears to be a viable alternative to thermal drying. However, transport phenomena in EHD are not well understood, which limits practical applications of EHD for drying of biomaterials.Scope and approachThis paper provides a comprehensive review of the fundamentals of electrically-induced physical processes relevant to the theory of EHD drying with particular emphasis on yet existing gaps in the knowledge.Key findings and conclusionsEssential phenomena pertinent to high-voltage electric field and electric wind were examined in terms of heat and mass transfer at the gas-solid interface. The gaps in the knowledge caused by simplifying assumptions in theoretical and experimental studies, as well as omitting some crucial electrically-induced transport phenomena were identified. These include: (i) quantifying energy balance in EHD drying, (ii) uncovering electrically-induced mechanisms of mass transfer in solid, gas and gas-solid boundary layer; (iii) identifying interactions and possibly synergetic effects between electric charge and heat/mass transfer processes; (iv) determining whether average electric wind velocity adequately represents spatial distribution of wind velocity in non-uniform electric field, (v) explaining of some experimental findings, such as temperature drop at the liquid-gas interface, distortion of the free water surface and tangential component of electric wind at the material plane.     

Food choice in low income populations – A review

The vast majority of publications on food acceptability and behavior have considered middle- or high-income populations. However, there is research focused on low-income populations which deserves attention considering that many millions worldwide suffer undernutrition and/or food insecurity. The objective of this review is to highlight what the authors considered to be the most relevant research in the area to thus bring attention to this sensitive area which requires further research. Although there is a certain overlap, the review is classified in the following areas: fruits and vegetables, obesity, food choice, indigenous populations, development of specific food products and, finally, what we consider to be the most promising or necessary research in the field of food choice in low-income populations.     

Dromedary camel milk proteins,a source of peptides having biological activities – A review

Many useful properties are assigned to camel (Camelus dromedarius) milk, which is traditionally used for the treatment of tuberculosis, gastroenteritis, and allergy in many countries. Some amino acid sequences, which are encrypted in the camel proteins, may play a beneficial role in human health once they are released from milk either in vivo during normal digestion or by proteolysis with purified enzymes or during bacterial fermentation. Similar to the bovine milk counterparts, camel milk bioactive peptides may display a variety of potential activities that were almost always unveiled from in vitro analyses: anti-microbial, anti-oxidative, anti-hypertensive, anti-inflammatory, and immunomodulatory activities. Today, there is a growing interest for bioactive peptides generated from camel milk. This paper reviews available data on the potential biological activities of the camel milk proteins and their peptides liberated either during milk fermentation with proteolytic bacterial strains or by enzyme hydrolysis with specific proteases or simulated gastro-intestinal digestion.     

Potato Glycoalkaloids: occurrence,biological activities and extraction for biovalorisation – a review

Potato tuber (Solanum tuberosum L.) is the fourth most important agricultural product after wheat, rice and maize. With a total production of 388 million in 2017, c.a. 70% of this total production is processed in developed countries, producing a large amount of potato peel waste (PPW) as by-product. Although PPW is considered as a zero-value by-product by the feed industry because it is too fibrous, for other recycling industries it is an inexpensive by-product due to its significant contents of some interesting nutrients particularly polyphenols and glycoalkaloids. In potato, and Solanum species in general, many glycoalkaloids, predominantly α-chaconine and α-solanine, have been chemically and structurally identified. However, further research is needed to expand the knowledge of the biological values of potato glycoalkaloids in order to develop a recycling process to extract these technologically and nutritionally interesting bioactive ingredients for different sectors, in particular, the agricultural, food and pharmaceutical ones, which are demanding natural, safe and eco-friendly ingredients.     

Superfruits: Phytochemicals,antioxidant efficacies,and health effects – A comprehensive review

The term “superfruit” has gained increasing usage and attention recently with the marketing strategy to promote the extraordinary health benefits of some exotic fruits, which may not have worldwide popularity. This has led to many studies with the identification and quantification of various groups of phytochemicals. This contribution discusses phytochemical compositions, antioxidant efficacies, and potential health benefits of the main superfruits such as açai, acerola, camu-camu, goji berry, jaboticaba, jambolão, maqui, noni, and pitanga. Novel product formulations, safety aspects, and future perspectives of these superfruits have also been covered. Research findings from the existing literature published within the last 10 years have been compiled and summarized. These superfruits having numerous phytochemicals (phenolic acids, flavonoids, proanthocyanidins, iridoids, coumarins, hydrolysable tannins, carotenoids, and anthocyanins) together with their corresponding antioxidant activities, have increasingly been utilized. Hence, these superfruits can be considered as a valuable source of functional foods due to the phytochemical compositions and their corresponding antioxidant activities. The phytochemicals from superfruits are bioaccessible and bioavailable in humans with promising health benefits. More well-designed human explorative studies are needed to validate the health benefits of these superfruits.     

Green tea extract: Chemistry,antioxidant properties and food applications – A review

Green tea is one of the most popular and extensively used dietary supplement in the United States. Diverse health claims have made for green tea as a trendy ingredient in the growing market for nutraceuticals and functional foods. Green tea extract contains several polyphenolic components with antioxidant properties, but the predominant active components are the flavanol monomers known as catechins, where epigallocatechin-3-gallate and epicatechin-3-gallate are the most effective antioxidant compounds. Additional active components of green tea extract include the other catechins such as epicatechin and epigallocatechin. Among these, epigallocatechin-3-gallate is the most bioactive and the most scrutinized one. Green tea polyphenols are also responsible for distinctive aroma, color and taste. Green tea extract can also be used in lipid-bearing foods to delay lipid oxidation and to enhance the shelf-life of various food products. This review outlines the chemistry, flavour components, antioxidant mechanism, regulatory status, food applications, and stability of green tea extract in food.     

A study by a genetic algorithm for optimizing the arrangement of the fibers on the damage to the fiber–matrix interface of a composite material

The objective of this work is to optimize the arrangement of the fibers to reduce damage to the fiber matrix interface of a composite material. The results obtained by the genetic algorithm based on the volume fraction of reinforcement show a good agreement between numerical simulation and the actual behavior of both materials T300/914 and PEEK/APC2, however, it would be interesting to see the effect of thermal stress on the optimization of the arrangement by the molecular dynamics method.