Tree species yielding edible fruit in the coffee-based homegardens of Kerala, India: their diversity, uses and management

The homegardens of Kerala are known for the high diversity of their species in both cultivated and managed plant communities, with fruit trees as one of the more important components. A study was conducted to quantify the density and diversity of both cultivated and non-crop trees that yielded edible fruit (hereafter, fruit trees) in coffee-based homegardens of the State. Among 101 species of fruit trees from 25 homegardens, 46 were cultivated and the rest were non-crop species. Cluster analysis of their relative density differentiated three clusters (Homegarden Types) which demonstrated variation in their structural characteristics. Tree density, Shannon index of diversity and evenness index in Homegarden Type 1 were significantly higher (P < 0.05) than in Homegarden Types 2 and 3. In the study area, the non-crop species most preferred for their fruits included Baccaurea courtallensis, Carissa carandus, Chrysophyllum roxburghii, Feronia elephantum, Flacourtia montana, Garcinia xanthochymus, Madhuca indica, Madhuca longifolia, Mimusops elengi, Zizyphus mauritiana and Zizyphus rugosa. Collection of fruits of cultivated species is primarily by special collection trips, whereas that of non-crop species is generally during casual visits by adults and children. In the study area, cultivated species were actively managed (eg. weeding, fertiliser application and pruning of branches) but for non-crop species management was relatively passive (toleration and protection). Contrary to the general fear at the global level that homegardens are losing their traditional characteristics and are being transformed into species-poor, cash-crop production systems, the homegardens of the present study are examples in which many traditional ecological features are being maintained. Recommendations, drawn from the results, for enhancing the economic value of homegardens and ensuring food security include tree improvement, domestication and sustainable cultivation of non-crop fruit trees in order to conserve diversity.     

可食性膜在果蔬贮藏保鲜中的应用

主要介绍可食性膜的概念、特点、类型及其在果蔬保鲜中的应用。     

可食性膜在果蔬贮藏保鲜中的应用

主要介绍可食性膜的概念、特点、类型及其在果蔬保鲜中的应用。     

Determination and the hygienic-toxicologic significance of patulin in fruit and fruit products]

The combination of extracting, chromatographic and fluorescence densitometric steps permits to determine patulin in fruits and fruit products with great precision and sensitivity. The limit of detection is 10 microgram/kg; the recovery rates range from 86 to 92% with a variation coefficient lying between 5.6 and 13.6%. Interferences due to patulin-simulating substances are widely excluded. Patulin concentrations ranging from 0.3 to 42 mg/kg were found in the brown-rotten portions of apples. Juices domestically prepared from healthy fruits and fruits rid of rotten portions, respectively, contained no patulin. On the contrary, patulin concentrations ranging from 0.02 to 0.3 mg/l were observed in commercial apple juices. As to products with subsequent mould infection, patulin values up to 50 mg/l were found in apple juices, and up to 0.4 mg/kg in peach preserves. In a further 24 commercial fruit and vegetable juices, patulin was not detectable even not in cider, in cereals which had gone mouldy spontaneously, and in bread samples. The fruits and fruit products were analysed not only for patulin, but also for aflatoxin and ochratoxin; the latter two, however, were found in none of the samples examined. The possibilities of manufacturing patulin-free products are discussed.     

含纤维果蔬饮料的生产技术

介绍了并讨论以柑桔，胡萝卜，蕃茄等水果蔬菜为原料生产含果蔬食物纤维饮料的生产工艺与设备。主要介绍混浊型果蔬饮料，清爽型果蔬饮料及其加工方法。     

Physicochemical properties and application of pullulan edible films and coatings in fruit preservation

The effects of water, sorbitol and a sucrose fatty acid ester (SE) on the water sorption behaviour and thermal and mechanical properties of pullulan‐based edible films as well as the physiological responses of fruit coated with pullulan have been studied. Incorporation of sorbitol or SE in pullulan films resulted in lower equilibrium moisture contents at low to intermediate water activities (a_w), but much higher moisture contents at a_w > 0.75; estimates of monolayer values (within 4.1–5.9 gH₂O kg^?1 solids) were given by application of the Brunauer–Emmett–Teller (BET) and Guggenheim–Anderson–DeBoer (GAB) models. A single glass–rubber transition (T_g), attributed to the polysaccharide component, was detected by calorimetry and dynamic mechanical thermal analysis (DMTA) at a sorbitol level of 15–30% DM. With both tests the strong plasticising action of water and polyol was evident in the thermal curves, and the T_g vs moisture content data were successfully fitted to the Gordon–Taylor empirical model. Multifrequency DMTA measurements provided estimates for the apparent activation energy of the glass transition in the range of ? 300–488 kJ mol^?1. With large‐deformation mechanical testing, large decreases in Young's moduli (tensile and three‐point bend tests) were observed as a result of water‐ and/or polyol‐mediated glass‐to‐rubber transition of the polymeric films. In the moisture content range of 2–8%, increases in flexural modulus (E) and maximum stress (σ_max) with small increases in moisture content were found for films made of pullulan or pullulan mixed with 15% DM sorbitol; a strong softening effect was observed when the water content exceeded this range. Addition of sorbitol increased the water vapour transmission rate of the films, whereas addition of SE had the opposite effect. Application of a pullulan/sorbitol/SE coating on strawberries resulted in large changes in internal fruit atmosphere composition which were beneficial for extending the shelf‐life of this fruit; the coated fruit showed much higher levels of CO₂, a large reduction in internal O₂, better firmness and colour retention and a reduced rate of weight loss. In contrast, similar studies on whole kiwifruits showed increased levels of internal ethylene, which caused acceleration of fruit ripening during storage. © 2001 Society of Chemical Industry     

Antibacterial activity of proteins extracted from the pulp of wild edible fruit of Bromelia pinguin L.

Bromelia pinguin L. is a natural source of bioactive compounds. The main purpose of this research was to isolate and characterize bioactive proteins from its fruit. B. pinguin proteins were fractionated by gel filtration chromatography, and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The antibacterial activity of the proteins was analyzed against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, and the enzymatic activity was evaluated by protease activity and trypsin inhibitions assays. Protein fraction obtained by gel filtration chromatography exhibited antibacterial activity against E. coli (minimum inhibitory concentration [MIC] 0.3492 mg/mL) and S. aureus (MIC 0.6845 mg/mL). The proteolytic activity of the fraction was 0.985 U_cas/mL. The substrate-sodium dodecyl sulfate-polyacrylamide gel electrophoresis assay detected protease inhibitors with molecular weights of 43 and 74 kDa. Antibacterial studies of E.coli and S. aureus were determined by comparing the protein fraction with different antibiotics. The antibacterial activity of proteins extracted from the pulp of the fruit of Bromelia pinguin L. could be related to the presence of enzymes, protease inhibitors and peptides.     

Positive effects of glycosylated anthocyanin isolated from an edible berry fruit (Acanthopanax sessiliflorum) on its antioxidant activity and color stability

A major chromatographic peak of anthocyanin from ogaja (Acanthopanax sessiliflorum) fruit represented 95.4% of total absorbable compounds at 518 nm. The mass-to-charge ratio (m/z) of this colorant was determined to be 581 by LC-MS, which was identical to the molecular mass of cyanidin-3-O-sambubioside. After acid hydrolysis of the purified anthocyanin fraction, it was structurally confirmed by thin layer chromatography (TLC) and high-performance anion exchange chromatography (HPAEC) analyses. As a result, the sugar moieties linked to cyanidin were glucose and xylose. The purified cyanidin-3-O-sambubioside and cyanidin had greater antioxidant activities than l-ascorbic acid by both DPPH and ABTS methods. Cyanidin-3-O-sambubioside was more stable than cyanidin in the response to heat (80 °C), and both fluorescent and UV light. l-Ascorbic acid had an adverse effect on the color stability of anthocyanin. In this study, we demonstrated that glycosylation on anthocyanidin would provide an effective protection barrier for its color stability against the exposure to various food processing conditions.     

Study of the microbial diversity and antimicrobial properties of Irish edible brown seaweeds

Brown Irish edible seaweeds, Himanthalia elongata, Laminaria sachharina and Laminaria digitata, were evaluated for the microbiota in raw and heat processed form. Raw seaweeds showed complete absence of aerobic mesophiles, halophiles, yeasts and molds. However, heating at 85 °C for 15 min resulted in spore germination. Bacterial counts as high as 10⁷ were observed for aerobic mesophiles and halophiles. Heating above 95 °C for 15 min resulted in complete inactivation of surface microflora. Bacteria belonging to Bacillaceae, Paenibacillaceae, Moraxellaceae and Enterobacteriaceae family were identified by 16S rRNA sequencing. In vitro antimicrobial activity of the methanolic extracts of the seaweed on food pathogenic and food spoilage bacteria were also evaluated. The seaweeds in their raw state had almost 100% inhibition against Listeria monocytogenes; 98% and 93% inhibition was achieved against Pseudomonas aeruginosa by H. elongata and L. saccharina extracts, respectively. Heating the seaweeds resulted in the reduction of antimicrobial activity as compared to raw. The effect was more pronounced against Gram negative bacteria.     

基于鱼皮明胶的可食膜改性及其应用

鱼皮明胶是一种资源丰富、具有良好成膜性的蛋白源,可食性鱼皮明胶膜的研制已成为食品包装领域的研究热点。本文介绍了鱼皮明胶的基本结构和特性,详细综述了鱼皮明胶可食膜的改性及其应用,旨在为鱼皮明胶可食膜的开发利用提供依据。      

食用前牛乳的污染及其对策

本文重点介绍如何预防和消除牛乳从产生到包装各种污染的形成,包括饲料安全、微生物污染、包装后污染等方面的问题.     

梧州霉豆腐渣中微生物群落多样性及食用安全性分析

目的：梧州霉豆腐渣是广西地方特色发酵食品,研究其微生物群落多样性和其有害真菌毒素残留量,是保证其食用安全性和提高产品质量理论基础。方法：先提取样品的总DNA,利用高通量测序技术进行16s rDNA和真菌区域ITS进行PCR扩增及Miseq测序分析,然后再利用超高效液相质谱联用仪同时测定样品中：黄曲霉毒素、赭曲霉毒素、桔青霉素、脱氧雪腐镰刀菌烯醇、玉米赤霉烯酮、T-2毒素、伏马毒素等16种真菌毒素残留。结果：高通量测序获得细菌Tag数目51821个,OTU数目57个,主要为考克氏菌属(Kocuria)占比25.90 %,肠球菌属(Enterococcus)占比18.73 %,坂崎肠杆菌属(Cronobacter)占比14.78 %,皮生球菌属(Dermacoccus)占比9.27 %；真菌Tag数目56741个,OTU数目6个,主要为链孢霉属(Neurospora),占比达到98.17%；其常见16种真菌毒素残留量未检出；结论：通过研究发现梧州霉豆腐渣具有丰富的微生物菌落多样性和特色菌群组成结构,初步推测其特征“红毛”为链孢霉(Neurospora),在正常烹饪加工下梧州霉豆腐渣食用安全性是有保证的。     

Bioactive compounds and antioxidant capacities in different edible tissues of citrus fruit of four species

Different edible tissues of citrus fruit, namely juice sacs (JS), segment membrane (SM), and segment (Seg), of four species, were examined for contents of bioactive compounds and total antioxidant capacities (TAC) by ferric reducing antioxidant power (FRAP) assay. Two flavanones (naringin and hesperidin) were identified by HPLC; hesperidin accounted for 18.5–38.5% of the total phenolics in the species Citrus unshiu, Citrus reticulata, and Citrus sinensis, while naringin was only found in Citrus changshanensis and it accounted for 53.7% of the total phenolics in SM of this species. In SM of all selected species, the contents of phenolic compounds and TAC were significantly higher than those in JS and Seg. Highest total phenolics, total flavonoids, naringin, and TAC were found in SM of C. changshanensis, while the highest carotenoid content was found in JS of C. reticulata. The contribution of vitamin C to TAC ranged from 26.9% to 45.9% in JS and Seg of all selected species. In SM, however, a high contribution from hesperidin was observed in C. unshiu (54.0%), C. sinensis (46.7%) and C. reticulata (30.0%). The results indicated that SM of citrus fruit were high in contents of bioactive compounds and TAC; it is thus recommended to consume citrus fruit with all edible tissues rather than juice or JS alone.     

Ascorbate oxidase from starfruit (Averrhoa carambola): preparation and its application in the determination of ascorbic acid from fruit juices

A study was conducted to utilize ascorbate oxidase (AAO) from very immature starfruit for the enzymatic determination of ascorbic acid (AsA) in colored samples. The enzyme preparation was carried out by a combination of (NH₄)₂SO₄ fractionation, DEAE-Toyopearl 650 M and ultrafiltration. A calibration curve for AsA was constructed by plotting the amount of AsA oxidized by the enzyme at a specified reaction time against the absorbance. The curve showed a linear relationship in the range of 0–100 μg ml⁻¹ AsA used. Using the plot, the values of AsA in juice samples were determined and compared with the conventional 2,6-dichloroindophenol method.     

Evaluation of nutritional and nutraceutical potentials of three wild edible mushrooms from Similipal Biosphere Reserve,Odisha, India

A variety of edible mushrooms are growing in Similipal Biosphere Reserve (SBR), some of which are used as ethno-medicine by indigenous tribals. In the present study, three wild edible mushrooms viz., Russula vesca, Russula delica and Termitomyces eurrhizus of SBR were analyzed for their nutritional and mineral contents along with antioxidant and antibacterial potential. The results showed that these three mushrooms are rich sources of nutrients (protein, carbohydrate, starch, reducing sugars and low fats), micronutrients (vitamins and carotenoids) and minerals (P, K, Mn, Co, Ni, Cd, Fe) with promising bioactive properties (antioxidant and antibacterial potentials). In general, these mushrooms revealed high amounts of proteins (22.82–35.17 g/100 g) and carbohydrates (45.68–63.27 g/100 g) and low contents in fats (2.03–4.62 g/100 g), while micronutrients (vitamins and carotenoids) and minerals were present in significant amounts. The antioxidant potentials of three different solvent extracts (ethanol, methanol and aqueous) of studied wild mushrooms showed strong antioxidant properties (ABTS, DPPH, H₂O₂ and metal chelating activities) with scavenging potential up to 89 % at concentration 100 μg/ml. Total phenol content was found between 21.92–41.99 mg catechol/g extract and flavonoid 2.53–7.52 mg quercetin/g extract. The studied mushrooms possess moderate antibacterial properties with zones of inhibition ranging from 13 to 30 mm against six human pathogenic bacteria which are comparable with Amphoxyllin standard. Being a source of nutrients and molecules with medicinal potential, the studied mushrooms can be used in human diet as nutraceuticals/functional foods for maintaining and promoting health, longevity and life quality.     

蔬菜硝酸盐污染现状及其食用安全性评价

通过分析测定9种主要蔬菜70个样品的硝酸盐含量,发现镇江地区根、茎、叶类蔬菜硝酸盐含量严重超标,其中尤以小青菜、茼蒿、芹菜、萝卜、蕹菜和苋菜最为突出,莴苣其次,生菜和土豆则较轻。同时评价了蔬菜的食用安全性,并提出了蔬菜硝酸盐污染的防治对策。