Chemical analysis of edible aromatic plants growing in Tanzania

The volatiles from the aerial parts of edible plants growing in Tanzania, Leucas glabrata, Plectranthus laxiflorus, Salvia nilotica and Vernonia smithiana, were investigated by GC and GC/MS. Thirty-five compounds were identified from L. glabrata, representing 80.4% of the total oil; forty-three from P. laxiflorus (86.7%); twenty-four from S. nilotica (94.3%); and thirty-nine compounds from V. smithiana (92.9%). Among the identified components, menthone, (p + o)-cymene, trans-caryophyllene and caryophyllene oxide were found as the main ones. Furthermore, the essential oils were investigated for their antimicrobial activity as well as for their antiradical activity, through the DPPH method. Upon antimicrobial assays, the oil of V. smithiana showed very strong antimicrobial activity against Gram-positive bacteria, oral pathogens and pathogenic fungi; the oil of P. laxiflorus also exhibited strong activity, mostly against Gram-positive bacteria and especially oral pathogens, while L. glabrata showed strong activity against all assayed bacteria. The essential oil of S. nilotica appeared to have the most antioxidant activity but was almost inactive against all tested microorganisms.     

Radiation preservation of foods of plant origin. Part V. Temperate fruits: pome fruits, stone fruits, and berries

The current status of research on the application of ionizing radiation for improving the storage of temperate fruits, i.e., apple, pear, peach, nectarine, apricot, cherry, plum, strawberry, bilberry, cranberry, raspberry, and black currant, is reviewed. Changes in fruit metabolism, chemical composition, texture, and organoleptic quality attributes are discussed with reference to the irradiation dose. The feasibility of using radiation either alone or in conjunction with heat treatment, refrigeration, and controlled atmospheres (CA) for the control of storage decay caused by fungal pathogens is considered. Areas of further research are suggested before irradiation could be considered for practical application in some of these temperate fruits. The recent trends in the possible use of irradiation for disinfestation of certain pome and stone fruits and the prospects for the commercial utilization of irradiation for improving the market life of strawberries are discussed.     

Nutritive values of Nepalese edible wild fruits

Summary The nutritive values of forty edible wild fruits of Nepal were determined in terms of total dry matter, sugar, protein, total ash and sodium, potassium, magnesium and calcium. It was concluded that most of the wild fruits are comparable to cultivated fruits in nutritive values and, therefore, may be considered as suitable for cultivation.

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Nährwert der eßbaren Wildfrüchte von Nepal

Zusammenfassung Der Nährwert von 40 eßbaren Wildfrüchten von Nepal wurde bestimmt. Die Werte der meisten wilden Früchte sind vergleichbar mit denen von kultivierten Früchten. Einige der Wildfrüchte können zur Kultivierung empfohlen werden.

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This work was sponsored by the Research Division, Rector's office, Tribhuvan University     

Biological evaluation and quantitative analysis of antioxidant compounds in pulps of the Amazonian fruits bacuri (Platonia insignis Mart.), ingá (Inga edulis Mart.), and uchi (Sacoglottis uchi Huber) by UHPLC‐ESI‐MS/MS

Bacuri, ingá, and uchi are Amazon fruits consumed specially in the North region of Brazil. Due to their large consumption and the lack of knowledge regarding its chemical composition, these fruits were studied in relation to their Antioxidant chemical constitution. The total phenolic content ranged from 3.86 ± 0.47 to 33.38 ± 1.51 mg GAE/100 g, and the total flavonoid content ranged from 1.75 ± 0.22 to 19.44 ± 0.87 mg QUERE/100 g, where the contents showed a significant correlation with DPPH and ABTS antioxidant assays. Thus, UHPLC‐MS/MS was applied do quantify selected compounds, been citric acid the most abundant for all fruits. Furthermore, samples were screened for their α‐glycosidase and lipase inhibitory effects, in addition to their antimicrobial potentials. Bacuri showed the highest antioxidant and α‐glycosidase inhibitory capacity (IC₅₀ 15.20 μg/mL), whereas uchi and its main metabolite bergenin displayed moderate antimicrobial activities. The results shed light into the potentials of Amazonian fruit sources.

Practical applications

Plant phenolics are essential components of functional foods, due to their antioxidant and enzyme inhibition activities, which are directly linked to several diseases prevention. This is the first study about the quantification of antioxidant compounds in the Amazonian fruits: bacuri, ingá, and uchi. Although they are quite consumed in the North region of Brazil, there are no bio‐products made from them. This study aimed to elucidate the knowledge about the chemical composition and potentialities within these fruits with the practical purpose of highlighting them to future commercial applications. In addition, once we indicate their capabilities, we contribute with local populations in respect to the production of such fruits, which still is a family activity.     

Chemical and sensory characterisation of aroma of Viburnum opulus fruits by solid phase microextraction-gas chromatography-olfactometry

The aroma profile of four cultivars of Viburnum opulus and one cultivar of V. opulus var. sargentii fruits was studied by solid phase microextraction of headspace volatiles and subsequent analysis by gas chromatography, mass spectrometry and olfactometry (SPME-HS-GC-MS-O). In total, 41 compounds were identified, 3-methyl-butanoic acid (63.0-71.8% of identified volatile organic compounds) being the major constituent in the three V. opulus cultivars, while 2-octanone was dominant in one cultivar of V. opulus and in V. opulus var. sargentii, amounting to 28.1% and 25.6% of identified volatile compounds, respectively. Ten odour active compounds were detected and characterised by the trained panel of judges in the course of GC-O by using detection frequency analysis (DFA). 3-Methyl-butanoic and 2-methyl-butanoic acids as well as linalool and ethyl decanoate were found to be the main odour active components for V. opulus aroma.     

Free and bound flavour components of Amazonian fruits: 3-glycosidically bound components of cupuacu

The total quantity (11.7 mg/kg of pulp) of aglycones released by enzymatic hydrolysis of the glycosidic extract indicates a significant aroma potential for cupuacu. Among the 47 aglycones identified, 24 are not present in the free volatile fraction, among them, 4-methylguaiacol, 4-propylguaiacol, 2,6-dimethyl-octa-1,7-dien-3,6-diol, 2,6-dimethyl-oct-7-en-1,6-diol, homovanillic acid, 2-methyl-but-3-en-1-ol and acetic acid. The quantitatively most important aglycones are 3-methyl-butan-1-ol, 2-phenylethanol, linalol, (Z)-2,6-dimethyl-octa-2,7-dien-1,6-diol, butan-1-ol and hexan-1-ol. The methylated alditol acetates analysis of monosaccharides released by acid hydrolysis of the heterosidic extract, indicates that glucose is involved in glucosidic and glycosidic structures. Moreover, rhamnopyranose and xylopyranose units, bound in the terminal position, suggest the presence of rutinosides and small amounts of primeverosides. Six glucosides, hexyl, benzyl, 2-phenylethyl, (R) and (S)-linalyl and geranyl β- -glucopyranosides, five rutinosides, benzyl, (R) and (S)-linalyl, -terpineyl and 2-phenylethyl rutinosides and 3-methyl-but-2-enyl vicianoside were identified by GC–EIMS after TFA derivatization of the crude heterosidic fraction. Moreover, four linalol oxides, octyl, 3-methyl-butyl β- -glucopyranosides and hexyl, octyl, two linalol oxides and 3-methyl-butyl rutinosides, have been tentatively identified from their TFA mass spectra. Some glucosides are probably substituted by malonyl and unidentified acyl residues.     

Intrinsic mineral labeling of edible plants: methods and uses

The fate of minerals can be conveniently studied through intrinsic labeling techniques. The mineral of interest is biologically incorporated into the food in a form that can be distinguished analytically from the natural form of the element. Radiolabels have traditionally been used to study such problems as the uptake of minerals by plants, the gross and subcellular mineral distribution in plant tissues, the form and associations of the deposited mineral, and the bioavailability of minerals to animals and humans. The use of stable (nonradioactive) isotopes as a label offers the potential of safely studying bioavailability of minerals from individual foods in human population groups of all ages using foods processed in normal food handling and processing facilities.     

Chemical Modification of Guaran Gum. Part 2: Cyanoethylation

Guar gum was cyanoethylated under a variety of conditions. It is shown that the extent of reaction increases by increasing the acrylo-concentration nitrile and decreases by increasing the reaction temperature. Cyanoethyl guaran pastes are characterized by non-Newtonian pseudoplastic behaviour and may be described by the power low T = kDⁿ in which the rheological parameters k and n depend mainly on the type of the derivatives. The apparent viscosity of these derivatives depends on its nitrogen content as well as the rate of shear.     

Evaluation of the Amazonian fruit Ambelania acida: Chemical and nutritional studies

Ambelania acida is native to the Amazon region, with few published studies of its fruits. We examined the proximate composition of its fruits, including minerals, fatty acids, volatile organic compounds (VOCs), as well as its antioxidant capacity. The protein contents (2.61%) of the pulp and seeds (13.6%) were higher than observed in other taxa of the family or in other tropical fruits. Peel and pulp showed high contents of potassium, calcium, and magnesium, and the potassium content in the pulp was 1125 mg/100 g. The peel had higher contents of total phenolics, tannins, and ortho-diphenols than the pulp, as well as better antioxidant activity as evidenced by 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), and Fe²⁺ chelating activity assays. GC-MS analyses identified 42 VOCs in the peel and pulp, with more than 90% being classified as terpenes. Eleven types of fatty acids were identified in the lipid fractions of the peel, pulp, and seeds. Linoleic acid, an essential fatty acid for humans, was the principal fatty acid in the edible portion of the fruit, therefore, evidencing its nutritionally significant profile for the fruits when considering the relationship among polyunsaturated, saturated, and monounsaturated fatty acids. The information gathered here indicates that this native fruit is a healthy food source and its cultivation and consumption should be stimulated.     

The glycoalkaloid content of some edible solanaceous fruits and potato products

The glycoalkaloid contents of three edible solanaceous fruits (aubergine, red and green peppers) have been found to be less than 10 mg 100 g^?1 fresh weight. Commercial potato products, such as potato crisps, chips and tinned new potatoes, have been found to contain similar low levels which are within those accepted as safe by breeders of commercial potatoes.     

食用油在煎炸过程中的化学变化

煎炸技术是一种古老的食物烹饪方式,其以油脂为传热介质使食物从外到内加热至成熟。但是,煎炸过程的高温、多水和富氧环境会使食用油发生氧化、水解,以及聚合或裂解等多种化学反应。1氧化反应油脂变质是导致食用油产生毒害性的关键因素,而脂类氧化是油脂变质的主要原因之一。     

Citrus phenylpropanoids and defence against pathogens. Part I: Metabolic profiling in elicited fruits

Penicillium spp. are among the major postharvest pathogens of citrus fruit. Induction of natural resistance in fruits constitutes one of the alternatives to chemical fungicides. Here, we investigated the involvement of the phenylpropanoid pathway in the induction of resistance in Navelate oranges by examining changes in the metabolic profile of upon eliciting citrus fruits. By using both HPLC-PDA-FD and HPLC-PDA-QTOF–MS allowed the identification of several compounds that seem to be relevant for induced resistance. In elicited fruits, a greater diversity of phenolic compounds was observed in the flavedo (outer coloured part of the peel) when compared to the albedo (inner white part). Moreover, only small changes were detected in the most abundant citrus flavonoids. The coumarin scoparone was among the compounds with the highest induction upon elicitation. Two other highly induced compounds were identified as citrusnin A and drupanin aldehyde. All three compounds are known to exert antimicrobial activity. Our results suggest that phenylpropanoids and their derivatives play an important role in the induction of resistance in citrus fruit.     

牡蛎糖原的研究(I)——牡蛎糖原的分离提取和化学组成

用热碱法提取牡蛎中的糖原,经纯化后得到几乎不含有蛋白质的糖原样品。凝胶过滤色谱结果表明,牡蛎糖原相对分子质量在数百万至数千万之间。气相色谱测定结果表明,牡蛎糖原只含有葡萄糖残基,是一种均一多糖。     

牡蛎糖原的研究(Ⅰ)--牡蛎糖原的分离提取和化学组成

用热碱法提取牡蛎中的糖原，经纯化后得到几乎不含有蛋白质的糖原样品。凝胶过滤色谱结果表明，牡蛎糖原相对分了质量在数百万至数千万之间。气相色谱测定结果表明，牡蛎糖原只含有葡萄糖残基，是一种均一多糖。     

A study of the modelling and characterisation of compression garments for hypertrophic scarring after burns. Part 2: characterisation of compression garments

Compression therapy is the universally accepted treatment for the management of hypertrophic scarring after severe burns. A review of the type of treatments for burns and type of compression garments commercially available is discussed in Part 1 of this paper (Anand, Kanchi Govarthanam, & Gazioglu, in press). A refined model was also designed to predict the sub-garment pressure more accurately, irrespective of the shape and size of the limb (see Part 1, in press). The thermophysiological properties of the compression garment provide comfort by preserving body temperature and moisture output close to their normal levels. In this study, the dimensional, mechanical and thermophysiological properties of four fabrics procured from different sources were thoroughly studied and compared. The study was aimed at the determination of their suitability to be utilised for the management of hypertrophic scarring. It was established that one of the fabrics investigated possessed superior properties in comparison to the other three fabrics. It was also demonstrated that the characteristics of this particular fabric can be further enhanced for its suitability for use as a compression garment for this specific area of application.     

Dry beans of Phaseolus. A review. Part 1. Chemical composition: proteins

Beans of Phaseolus are important food crops both economically and nutritionally and are cultivated and consumed worldwide. With ever‐rising costs of meats and fresh fruits and vegetables, dry beans are expected to contribute more to the human nutrition in coming years. Traditionally, they have been referred to as “poor man's meat” and have contributed significantly to the diets of many people of several countries in Asia, Africa, Middle East, and South America. In recent years, a renewed interest in bean research in Western European countries and the U.S. is evident. In this review, certain biochemical, technological, nutritional, and toxicological aspects are discussed and the limitations and problems associated with dry beans of Phaseolus as human food are addressed.     

Chemical Modification of Proteins Part 6. Further Studies on Gelation of Casein after Modification by Dialdehyde Starch

The physical and chemical changes in casein during the gelation owing to the chemical modification by dialdehyde starch (DAS) in 8–10% solution were studied using electron-microscopy, measuring the mechanical properties (shear deformation), turbidimetric titration, and determination of amino groups. The gelation which proceeds during a storage time of 2 weeks is accomplished by the formation of a super-molecular network structure. Depending on the conditions of modification (pH, percentage of DAS, protein concentration) a more or less dense network is formed. An increase of pH (in the range of pH 6,3–9,7) leads to an increase of gelation speed, which favours the formation of irregular network structures. The denser the network formed the smaller is the shear deformation measured by the device of Tolstoi. During the storage of the gels the plastic component of compliance decreases to a greater amount than the elastic one. Therefore the relative amount of elastic component increases. During the reaction with DAS the maximum of turbidity of the protein (solubility minimum) shifted to lower pH owing to a blockage of positively charged groups. On the contrary to the changes measured by physical methods, this shift is complete soon after a 1 day storage. Similarly the blockage of amino groups is finished in the most cases this time too.     

Purification,characterisation and antioxidant properties of a novel polysaccharide from Physalis pubescens L. fruits

Considering the medicinal and edible properties of Physalis pubescens L. fruit, the plant has a long history of cultivation in China. In the current study, a novel polysaccharide (PPL-1) was successfully obtained from P. pubescens fruits using multi-column techniques. The chemical characterisation of the polysaccharide was achieved by acid hydrolysis, determination of weight average molecular mass, thermogravimetric and Smith degradation analyses, in addition to ultraviolet, Fourier transform infrared spectroscopy, one- and two-dimensional nuclear magnetic resonance spectroscopy. According to the structural analyses, PPL-1 consisted of rhamnose, arabinose, fructose, mannose and glucose with a relative molar ratio of 0.39:0.12:0.02:0.03:0.44. The average molecular weight of PPL-1 was 7.3 kDa and it was mainly composed of (1 → 3) and (1 → 6) linkages. PPL-1 exhibited not only scavenging effects on 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals but also hydrogen peroxide-induced oxidative stress in SH-SY5Y cells effectively by decreasing malondialdehyde content and increasing total antioxidant capacity, superoxide dismutase and glutathione peroxidase activity levels.     

Nanoemulsion as advanced edible coatings to preserve the quality of fresh-cut fruits and vegetables: a review

The increasing consumer's demand regarding the healthy diet has promoted the research towards novel approaches for preserving minimally processed fruits and vegetables without the necessity of using preservatives. Emulsion-based edible coatings technology is considered a valuable alternative to improve fresh-cut fruit and vegetable quality. This review discusses some recent advances for the preservation of the quality and safety of fresh-cut fruits and vegetables with respect to the use of nanoemulsion-based edible coatings as carrier of functional compounds such as antimicrobial agents, antioxidants and texture enhancers. It focuses especially on the use of natural functional compounds in food preservation as an alternative to synthetic additives. Moreover, the preparation and characterisation of nanoemulsion are also reviewed.     

Chemical Modification of Guaran Gum. Part 3: Carboxymethylation in non-Aqueous Medium

Guar gum was isolated from the seeds and subjected to modification via non-aqueous carboxymethylation. Highly substituted carboxymethyl guaran derivatives could be obtained via repeating the reaction four times, where a product of degree of substitution (D.S.) 2.07 was obtained indicating that the free hydroxyl groups of both glucose and mannose (which form the main constituents of guaran) can react with monochloro acetic acid. The modification increases the solubility of the gum in cold water, and increases the stability of its pastes to microorganisms. Pastes of these derivatives are characterized by non-Newtonian pseudoplastic behaviour regardless of their D.S. or the measuring temperature, while their apparent viscosity decreases by increasing the D.S. and/or the measuring temperature.