Buckwheat starch: Structures,properties, and applications

BackgroundThere is increasing interest in utilization of buckwheat for healthy food applications. Common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum) are cultivated in Asia, Europe, and Americas for various food formulation and production. Starch, the major component of the seeds, may account over 70% of the dry weight. Therefore, it is expected that, to a large extent, the quality of starch determines the quality of buckwheat food products. Furthermore, Buckwheat starch has great potential for various food and non-food uses due to the unique structural and functional features.Scope and approachThis review summarises the current knowledge of chemical composition, chemical structure of amylose and amylopectin, physical structure of granules, physicochemical properties, enzyme susceptibility, modifications, and uses of buckwheat starch. Suggestions on how to better understand and utilise the starch are provided.Key findings and conclusionsAmylose contents of buckwheat starch ranged from 20 to 28%. Starch granules are most polygonal with size ranging from ∼2 to 15 μm and an average diameter of ∼6–7 μm. The polymorph is A-type. The amount of extra-long unit chains of amylopectin (DP > 100) is higher than that of cereal amylopectins. Low glycaemic index of buckwheat food products could be attributed to the non-starch components. Buckwheat starch has been used as fat replacer, ingredient for extruded products, nanocomposite material, and fermentation substrate for alcoholic beverage. It may be concluded that buckwheat starch can be a unique source of specialty starch for innovative food and non-food applications.     

Crosslinking in polysaccharide and protein films and coatings for food contact – A review

BackgroundCrosslinking is the process of forming tridimensional networks by linking polymer chains by covalent or noncovalent bonds. It is useful for polysaccharide- and protein-based films and coatings to be applied to food surfaces, enhancing their water resistance as well as mechanical and barrier properties. Crosslinkers intended to be used for food contact materials must present low toxicity.Scope and approachThis review is a summary of the main crosslinking agents which have been used for protein and polysaccharide films and coatings, and which may be applied as food contact materials. The study emphasizes the mechanisms of crosslinking agents, the chemical groups involved, conditions for application, advantages and drawbacks, as well as examples of applications for food contact materials.Key findings and conclusionsCrosslinking is a promising technique to improve the performance and applicability of protein- and polysaccharide-based food contact materials, especially concerning their water sensitivity, which hinders many of their potential applications as food contact materials. Some aldehydes are very effective as crosslinkers, but they have been avoided in food contact materials because of possible migration of aldehyde residues to food, and less toxic compounds have been studied for those applications, such as phenolic acids, oxidized polysaccharides, and enzymes. Crosslinking techniques may help make protein- and polysaccharide-based materials more suitable for large-scale processing and applications in the future.     

Chemical and biological properties of feijoa (Acca sellowiana)

BackgroundFeijoa (Acca sellowiana) is native to South America and is recognised in some other parts of the world for its highly aromatic fruit. There has been increasing interest in developing feijoa for food product formulation and as fresh produce for consumption. Understanding the chemical composition and biological activities of different botanical parts of feijoa (fruit peel and flesh, leaf, and flower) provides a basis to support the current exploitation.Scope and approachThis mini-review summarises the recent advances in chemical composition and biological activities of different botanical parts of feijoa (fruit, leaf, and bud). Properties of feijoa are compared with those of other fruits. Processing feijoa for food applications is also reviewed. Future research directions on how to better utilize this crop are suggested.Key findings and conclusionsFejioa contains a range of bioactive components such as phenolic acids and flavonoids, dietary fiber, vitamin C, potassium, and essential oils. These compounds contribute to a range of claimed health effects, including antioxidant, anti-inflammatory, and antimicrobial activities of feijoa extracts. Consumption of fresh feijoa fruit should be moderate due to the presence of a relatively high level of soluble oxalate. Overall, feijoa has great potential to be developed as a sustainable crop.     

Changes in functional characteristics of starch during water caltrop (Trapa Quadrispinosa Roxb.) growth

This study was carried out to establish the changes of physicochemical properties of Taiwan’s water caltrop (Trapa Quadrispinosa Roxb.) starch at various stages of maturity during growth. Investigations showed that the dry matter and starch contents of water caltrop increased from 9.7% to 25.61% and from 49.4% to 79.4% (d.b.), respectively, as growth progressed (from 14th to 42nd day after fruit development). The shape of the starch granules was smooth, oval and poly-angular during the growth period. The granule size of starch increased with increase of physiological age, ranging from 19.4 μm to 32.2 μm. The X-ray diffraction patterns could be classified as a typical A-type crystalline structure. Swelling power and solubility of water caltrop starch increased with increases of growth time. Starches obtained from water caltrop at the early stage exhibited a lower gelatinization temperature (T_o, T_p, T_c) and gelatinization enthalpy (ΔH) than did the late stage of maturity. The rapid viscosity analyzer (RVA) parameters suggested that water caltrop starch paste had a low breakdown, and appeared to be thermo-stable, at the early harvest time. The pasting temperature, peak viscosity, final viscosity and setback value of water caltrop starch increased as growth progressed. Different starch granular size and amylose content could be the major factors influencing starch physicochemical properties during maturity.     

Effect of micronization on functional properties of the water caltrop (Trapa taiwanensis Nakai) pericarp

The aim of this study was to investigate the effect of micronization on the functional properties of the water caltrop (Trapa taiwanensis Nakai) pericarp (WCP). Three different micronization treatments were carried out, including wet milling (WM), freeze-dried milling (FDM) and hot-air dried milling (HDM). Seven fractions of micro-sized WCP were obtained for each treatment, using hammer and ball milling, consecutively. The ball milling treatment of WCP resulted in an increase of hydration properties (solubility, water-holding capacities, and swelling capacity) and oil-holding capacities due to the redistribution of fibre components from insoluble to soluble fractions. The cation-exchange capacity of WCP increased significantly with decreases in particle size after micronization by ball milling. The findings suggested that different micronization treatments could improve functional properties of the fibre components of WCP, which provide a good source of dietary fibre in food applications.     

The role of polyphenol oxidase and peroxidase in the browning of water caltrop pericarp during heat treatment

The mechanism of browning involving enzymatic browning was investigated in the pericarp of water caltrop, an Asian vegetable popular for its taste and medicinal properties. Polyphenol oxidase (PPO) and peroxidase (POD) activities were determined in pericarp at various times and temperatures. Water caltrop consisted of 44.22% moisture content, 37.23% crude fibre, and 2.63% crude protein. PPO and POD activities dropped from 62 and 38 units/g sample, respectively, as water temperature was increased from 30 to 80 °C. Optimum pH and temperature for PPO activity was at pH 5.0, 25–45 °C, and POD activity peaked at 60 °C. High PPO and POD activities at 40–50 °C resulted in degradation of phenolic compounds, which led to increased aggregation of browning pigments and discolouration (lower L-values) of the pericarp. Enzymatic browning was determined as the major factor in the browning discolouration of heat-treated water caltrop pericarp.     

Molecular structure and rheological character of high-amylose water caltrop (Trapa bispinosa Roxb.) starch

The molecular structure and rheological properties of high-amylose water caltrop (Trapa bispinosa Roxb.) starch cultivated in Vietnam were investigated. The water caltrop starch had 47.1% amylose and its molecular weight (Mw) was (4.77±0.27)×10⁶ g/mol, whereas the Mw was (2.07±0.10)×10⁷ g/mol for amylopectin. The average chain length of amylopectin was DP_n=19.0 and the proportions of A, B₁, B₂, and B₃ chains were 28.2, 50.3, 13.1, and 8.5%, respectively. The DSC thermogram of the water caltrop starch was broadly endothermic, with 2 distinct endothermic peaks at 73.6 and 80.7°C. Gel formation of water caltrop starch occurred rapidly, with an extremely high storage modulus up to approximately 1,200 Pa. High-amylose water caltrop starch paste had an extremely high final viscosity compared to that of other cereal starches. These rheological behaviors may have been due to the extremely high amylose content.     

Antiplasticization effect of water in amorphous foods. A review

Water is the most effective plasticizer in food matrices, decreasing glass transition temperature (T_g) and mechanical resistance and determining a softening effect with the increasing of its concentration. However an opposite effect (i.e. hardening, toughening) could be observed in some food and in specific moisture or a_w range and this is referred to an anti-plasticization effect. Several are the possible causes for this phenomenon and various are the factors that have been recognized to affect its occurrence in a food matrix: mechanical testing method, mechanical parameter tested, type of food (composition and micro-macrostructure).     

Modification of food ingredients by ultrasound to improve functionality: A preliminary study on a model system

The use of high-intensity ultrasound for food processing applications is being constantly explored. Extraction of gingerol from ginger, homogenisation of milk and generation of high quality emulsions from food ingredients are some examples where ultrasonication has been found to be efficient, at least in laboratory-scale trials. These ultrasonic processes primarily rely upon the physical effects of ultrasound. However, the potential restrictions and/or uses of the chemical effects generated by ultrasound-induced cavitation phenomena have often been overlooked. Our investigation shows that unwanted reactions between ultrasonically generated radicals and food ingredients could be minimised by selecting lower ultrasonic frequencies for food processing. However, high frequency ultrasound could also be used for food processing, provided suitable radical scavengers are present in the solution. Preliminary results identified the potential of sonochemical hydroxylation of phenolic compounds as an efficient way of enhancing the antioxidant properties of certain food materials. Overall, these investigations have enabled the development of strategies for management of radical sonochemistry in food processing applications.Industrial relevanceThe aim of this work is to identify the problems associated with the application of high power ultrasound in food processing in order to make ultrasonic food processing a safe, viable and innovative processing technology in food industry. Several food and chemical industries will be able to adopt sonochemical treatment to improve the quality and the productivity of specific products. As an adjunct to existing processing technologies the application of ultrasonics can reduce energy requirements and simplify formulation with less need to add ingredients as processing aids.     

Chemical composition and physical characteristics of water caltrop during growth

BACKGROUND: The aim of this study was to monitor the chemical composition and physical and morphological characteristics of two varieties of water caltrop during growth in order to determine the optimal harvesting time. RESULTS: The dry matter, starch and amylose contents and α‐amylase activity of fruits of both water caltrop varieties increased during the growth period. Mature fruits contained 142–156 g starch kg^?1 fresh sample and provided 684–697 kcal total energy kg^?1 fresh sample. Dry matter content and bulk density increased significantly from 67 to 207 g kg^?1 and from 0.57 to 1.58 g ml^?1 respectively as growth progressed. Morphological analysis showed that the size and number of starch granules increased as growth progressed. Moreover, both varieties contained substantial amounts of essential amino acids, most of which appeared to be superior to the FAO/WHO reference pattern. CONCLUSION: According to the chemical composition and physical characteristics of water caltrop determined in this study, the optimal harvesting time is 42 days after fruit development. Copyright © 2009 Society of Chemical Industry     

Edible halophytes of the Mediterranean basin: Potential candidates for novel food products

BackgroundRecent trends in the food science industry and consumers’ preferences for diversified diets suggest the consumption of wild greens not only as diet complements but also as healthy and functional foods for targeted conditions, rendering its commercial cultivation of major importance in order to avoid irrational gathering and genetic erosion threats. The Mediterranean basin abounds in wild edible species which have been used for food and medicinal purposes by human throughout the centuries. Many of these species can be found near coastal areas and usually grow under saline conditions, while others can adapt in various harsh conditions including high salinity.Scope and approachThe aim of this review focuses on listing and describing the most important halophyte species that traditionally have been gathered by rural communities of the Mediterranean basin, while special interest will be given on their chemical composition and health promoting components. Cases of commercially cultivated halophytes will be also presented to highlight their potential as alternative cash crops, while results from in vitro and in vivo health effects will be presented.Key findings and conclusionsThe recent literature has provided useful information regarding the potential of wild halophytes as promising ingredients in functional food products and/or as sources of bioactive compounds. However, further research is needed regarding the chemical characterization of these species under commercial cultivation practices, while further clinical and model trials have to be conducted to assess their long term bioactivity and elucidate potential toxic effects and regulations of safe consumption.     

Nanotechnology in the food sector and potential applications for the poultry industry

BackgroundSalmonellosis and campylobacteriosis are among the most frequently reported foodborne diseases worldwide. Commercial chicken meat has been identified as one of the most important food vehicles for Salmonella and Campylobacter infection. Increased poultry consumption has forced producers to explore methods for increasing their production output, while maintaining the affordability and safety of their products. While the forecast benefits of nanotechnology have yet to be fully realised, it has potential application at many points along the food production chain and offers the opportunity to meet these challenges.Scope and approachThe commercial poultry processing environment plays a significant role in reducing foodborne pathogens and spoilage organisms from poultry products prior to being supplied to consumers. This review discusses the potential opportunities and challenges for adopting nano-enabled technologies in the poultry industry, with respect to applications in microbiological food safety and quality assurance in the processing plant.Key findings and conclusionsSeveral possibilities exist to exploit the benefits of nanotechnologies in the poultry processing plant to enhance the microbiological safety and quality of products. Those applications include the adoption of nano-enabled disinfectants, surface biocides, protective clothing, air and water filters, packaging, biosensors and rapid detection methods for contaminants, and technologies that assure the authenticity and traceability of products. Although the fate and potential toxicity of nanomaterials are not fully understood at this time and scientific risk assessments are required, it is evident that there have been significant advances in the application of novel nanotechnologies in the food industry.     

Feasibility of using pulsed electric fields to modify biomacromolecules: A review

BackgroundThe challenges encountered in the utilisation of biomacromolecules as functional ingredients can be overcome through modification of their structural elements. Recently, researchers have shown an increased interest in the usage of non-thermal or chemical free modification techniques to improve the stability and function of primary ingredients in the food, biomedical and pharmaceutical applications. This has led to the investigations of pulsed electric fields (PEF) technology as an alternative technique for enhancing modification of chemical reactions and microstructure of biomacromolecules.Scope and approachThe goal of this paper was to conduct a systematic review on the effect of PEF on the functional properties of proteins, polysaccharides and their blends, focusing on the configurational and conformational modifications in the microstructure due to the application of micro/millisecond electric field.Key findings and conclusionsPEF has potential to modify the microstructure and functional properties of biomacromolecules. PEF–induced modifications follow two primary mechanisms, i.e. electrochemical reactions and polarisation of the structural moieties. Critical PEF treatment intensity (E_C) is required for the onset of the microstructural changes in biomacromolecules. These changes are influenced by the settings and configuration of the PEF equipment, product characteristics (molecular weight, pH, conductivity) and system temperature. If properly managed, PEF treatment and subsequently the changes in molecular properties (i.e. molecular disintegration and network formation) could be tailored for the production of superior micro-/nano-structured products for various applications.     

Composition,physicochemical properties of pea protein and its application in functional foods

Abstract

Field pea is one of the most important leguminous crops over the world. Pea protein is a relatively new type of plant proteins and has been used as a functional ingredient in global food industry. Pea protein includes four major classes (globulin, albumin, prolamin, and glutelin), in which globulin and albumin are major storage proteins in pea seeds. Globulin is soluble in salt solutions and can be further classified into legumin and vicilin. Albumin is soluble in water and regarded as metabolic and enzymatic proteins with cytosolic functions. Pea protein has a well-balanced amino acid profile with high level of lysine. The composition and structure of pea protein, as well as the processing conditions, significantly affect its physical and chemical properties, such as hydration, rheological characteristics, and surface characteristics. With its availability, low cost, nutritional values and health benefits, pea protein can be used as a novel and effective alternative to substitute for soybean or animal proteins in functional food applications.     

Assessing functional properties of rapeseed protein concentrate versus isolate for food applications

Rapeseed protein concentrate (RPC) and isolate (RPI) were fractionated from rapeseed meal and their techno-functional properties were characterized. RPC prepared by aqueous ethanolic washing process yielded less refined and insoluble fractions with largely denatured protein. Hydrated insoluble RPC particles held 6.7 g water without swelling. RPI fractionated from aqueous extraction and ultrafiltration still contained certain phenolic compounds but protein nativity was preserved including a high protein solubility of 78%. RPC dispersion with 40 w/w % showed the highest apparent complex modulus G* among all rapeseed materials. In contrast, the G* for RPI dispersion increased upon heating, suggesting a thermal induced denaturation and gelation capacity of the proteins. Thus, a largely denatured RPC free of phenolic compounds or a native but phenolic containing RPI were obtained by the applied processing conditions, which differ in their techno-functional properties and thus have different promising application potential in food applications.Industrial relevanceThe growing demand for plant as opposed to animal protein has sparked the interest of exploring currently underutilized plant protein sources in food industry. Rapeseed by-products obtained after oil extraction are promising but the presence of anti-nutritional components in rapeseed meal presents a barrier for its usage in food products. Aqueous ethanolic washing or aqueous extraction combined with membrane filtration were applied to remove the antinutritional factors from rapeseed meal to yield rapeseed protein concentrates and even more refined isolates. In this work, the functional properties of the fractionated rapeseed materials were characterized for its relevance in food applications. The similarities of the rheological properties between rapeseed protein concentrates and soy materials, as well as presence of native proteins in RPI might suggest their potential for diverse in food industry applications.     

Gold nanoparticles: From synthesis,properties to their potential application as colorimetric sensors in food safety screening

BackgroundFood safety management and guarantee are the basic requirement during food processing, circulation, storage, and marketing. Elevating the ability to evaluate food quality and safety in a rapid, sensitive and reliable manner is of great importance in food industry. Recently, gold nanoparticles due to unique optical property, ease of functionalization and preparation, and high selectivity and sensitivity have received considerable attention in the field of food safety.Scope and approachGold nanoparticles exhibit distinguishable optical characteristic in different aggregated states and thus have been developed into simple colorimetric sensors for the quick detection of chemical contaminants in food samples. Herein, we reviewed the current methods for synthesis and functionalization of gold nanoparticles, strategies for fabrication of gold nanoparticle based colorimetric sensors and their applications in rapid analysis of food contaminant. Moreover, the inherent optical property of gold nanoparticles and their detecting principle have been highlighted. Finally, the main challenges and future efforts in developing such colorimetric sensors for food contaminants detection were discussed.Key findings and conclusionsGold nanoparticles as smart colorimetric sensors conform to the requirement of modern analysis, such as high selectivity, sensitivity, simplicity, celerity, and portability. Thus, they have great potential to be applied as power sensing tools for food safety screening.     

Research advances in traditional and modern use of Nelumbo nucifera: phytochemicals,health promoting activities and beyond

Abstract

Nelumbo nucifera, or sacred lotus, has been valuable for us to use as vegetable, functional food, and herb medicine for over 2,000?years. The purpose of this article is to systematically review the traditional/modern uses, chemical compositions and pharmacological activities on different parts of N. nucifera. Traditionally, this plant has been used to treat chronic dyspepsia, hematuria, insomnia, nervous disorders, cardiovascular diseases, and hyperlipidemia. Now, phytochemical investigations on different parts of N. nucifera have indicated a wide spectrum of at least 255 constituents belonging to different chemical groups, including proteins, amino acids, polysaccharides, starch, flavonoids, alkaloids, essential oils, triterpenoids, steroids, and glycosides. Meanwhile, its pharmacological activities, including anti-obesity, antioxidant, anti-inflammatory, cardiovascular, hepatoprotective, hypoglycemic, hypolipidemic, antitumor, memory-improving and antiviral activities, have also been reviewed, together with its applications in health food industry and clinic uses of its single plant or herbal formulae. Herein, this review will provide state-of-the-art overview on its traditional and modern uses in food industry and medicines, together with the comprehensive profiles of phytochemicals, and health promoting bioactivities of this valuable plant. In addition, the new perspectives and future challenges in the research on lotus are also outlined.     

Water quality for Espresso coffee

Espresso coffee extraction is the most common brewing method in Italy and it is becoming very popular in many other countries around the world. Water (including its ionic content) is an essential ingredient and its role in Espresso brewing must be taken into due consideration. It is well known that water treatment is necessary to remove possible off-flavours deriving from the disinfection performed at municipal waterworks as well as to prevent expensive professional Espresso coffee machine from scaling problems. However, there is little awareness of the direct effect of water composition on the quality of coffee beverages, particularly for Espresso coffee.     

Application of different nanocarriers for encapsulation of curcumin

Abstract

Curcumin is the main polyphenol of the curcuminoid class of turmeric, a well-known spice belonging to the ginger family. In addition to its common applications like coloring and antioxidant agent as food additives, it has a broad range of favorable biological functions, such as anti-inflammatory, anti-microbial, anti-diabetic activities, and anti-cancer potentials against various cancers. However, curcumin suffers from some limitations including short shelf life due to its poor chemical stability, low bioavailability due to its poor absorption, low water solubility, rapid metabolism and rapid systemic elimination. Nanoencapsulaion has been addressed as an innovative and emerging technology for resolving these shortcomings. In this review, the different delivery systems used for loading of curcumin have been considered and explained including lipid-based, chemical polymer and biopolymer-based, nature-inspired, special equipment-based and surfactant-based techniques. Also, implications of nanoencapsulated curcumin in food, pharmaceutical and cosmetic uses are discussed. In this sense, the relevant recent studies in the past few years along with upcoming challenges have been covered. Although incorporation of curcumin into nanocarriers can be a possible solution to overcome its inherent constraints, there are some rational concerns about their toxicological safety once they enter into the biological paths. Therefore, future investigations could focus on assessment of their biological fate during digestion and absorption within human body.     

Modeling incidence of lipid and sodium chloride contents on sorption curves of gelatin in the high humidity range

Water mobility and availability are predominant factors in controlling organoleptic and biological quality in food. To characterize and quantify the role of protein macromolecular mesh, sodium chloride and fat on the water retention in the high humidity range, sorption isotherms were measured at 20 °C. A specific method was used which provides rapid equilibrium and many experimental points in comparison with the standard saturated salt solution method. Experiments were carried out on gelatin gels to which either sodium chloride (0-45% w/w on an anhydrous gelatin basis) or vegetal hydrogenated fat (0-50% w/w on total sample mass) was added. Desorption isotherms of 40 points each were measured for each sample for a_w values in a range from 0.60 to 0.99. Results precisely show the specific behavior of water in a protein-sodium chloride mix for a_w values between 0.65 and 0.75. Water activity was then predicted from sample composition. Good agreement with measurements was obtained (1) assuming no incidence of lipids on water-holding capacity and (2) adapting a Ross-type model considering crystallization and introducing an interaction factor related to sodium chloride content.