Changes in ascorbic acid,polyphenol content and antioxidant activity in minimally processed cactus pear fruits

Cactus pear fruits (Opuntia ficus indica Mill, cv. ‘Gialla’) were manually peeled, then placed in plastic boxes sealed with a film with high permeability to gases, and kept at 4°C for 9 days. After 3, 6 and 9 days, chemical, physical, microbiological and sensorial parameters, total phenols, vitamin C and antioxidant capacity were determined. In-package gas concentrations were measured almost daily. Vitamin C and antioxidant capacity remained unchanged, while polyphenols decreased after 6 days in storage. Of the chemical parameters, only pH and acidity changed significantly, without however, adversely affecting sensorial properties. Microbiological growth was limited and fungal colonies were never visually detected.     

Folate content in processed legume foods commonly consumed in Egypt

Industrial food processing and household cooking are reported to affect folate content. This study examined the effects of industrial and household processing methods on folate content in traditional Egyptian foods from faba beans (Vicia faba) and chickpeas (Cicer arietinum). Overnight soaking increased folate content by ∼40–60%. Industrial canning including soaking, blanching and retorting did not affect folate content (p = 0.11) in faba beans, but resulted in losses of ∼24% (p = 0.0005) in chickpeas. Germination increased folate content 0.4–2.4-fold. Household preparation increased the folate content in germinated faba bean soup (nabet soup) one-fold and in bean stew (foul) by 20% (p < 0.0001). After deep-frying of falafel balls made from soaked faba bean paste, losses of 10% (p = 0.2932) compared with the raw faba beans were observed. The folate content (fresh weight) in the traditional Egyptian foods foul and falafel and in the beans in nabet soup was 30 ± 2, 45 ± 2 and 56 ± 6 μg/100 g, respectively. The traditional Egyptian foods foul, falafel and nabet soup are good folate sources and techniques like germination and soaking, which increase the folate content, can therefore be recommended.     

Phytosterols and tocopherols content of pulps and nuts of Brazilian fruits

Fruits and nuts from the North and Northeast regions of Brazil were collected to determine their phytosterol and tocopherol content. The species studied were Cotia nut (Aptandra spruceana M.), Brazil nut (Bertholletia excelsa H.B.K.), Mucajá (Couma rigida M.), Red Açaí (Euterpe oleracea M.), Inajá (Maximiliana maripa D.), Jenipapo (Genipa Americana L.), Buriti (Mauritia flexuosa L.) and Uxi (Endopleura uchi C.). Phytosterols were analyzed by GC–FID using β-cholestanol as an internal standard, while tocopherols were determined by RP-HPLC-DAD. The pulps of Mucajá (26–236 mg 100 g^–1), Inajá (119–285 mg 100 g^–1) and Jenipapo (216 mg 100 g^–1) showed the highest total phytosterol contents. Considering α-tocopherol equivalents, the pulps of Buriti (346.72 μg g^–1) and Uxi (200.92 μg g^–1) contained the highest vitamin E activity. Therefore, the results indicate that these fruits and nuts have great potential to be cultivated and marketed as alternative dietary sources for these bioactive compounds.     

Phenolic acid content of fruits commonly consumed and locally produced in Scotland

Despite fruit, vegetables and many processed products counting towards achieving the recommended five-a-day strategy, it is inevitable that produce choice will affect the benefits delivered. Fruits locally produced and commonly consumed in Scotland were compared for their phenolic acid content and form. The phenolic acid composition was highly variable, but the locally produced fruits were significantly (p < 0.001) higher in total concentration (1.61–4.89 g/kg compared to 0.06–0.22 g/kg). The majority of the phenolic acids were conjugated to other plant components, suggesting that any health benefits derived from these compounds are likely to be after they are released/metabolised by the colonic microbiota. Although the potential protective effects of the individual compounds will not be ascertained until the exact role of these compounds in disease prevention has been clarified, it is clear that the total amount of phenolic acids in the diet will vary enormously depending on the types of fruits consumed.     

Total antioxidant capacity of spices, dried fruits, nuts, pulses, cereals and sweets consumed in Italy assessed by three different in vitro assays

With the aim to expand the Italian total antioxidant capacity (TAC) database, the TAC values of 11 spices, 5 dried fruits, 7 sweets, 18 cereal products, 5 pulses, and 6 nuts were determined using three different assays and considering the contribution of bound antioxidant compounds in fiber-rich foods (i. e. cereals, legumes, and nuts). Among spices, saffron displayed the highest antioxidant capacity, whereas among dried fruits, prune exhibited the highest value. The TAC values of all the chocolates analyzed were far higher than the other sweet extracts measured. Among cereal products, whole meal buckwheat and wheat bran had the greatest TAC. Among pulses and nuts, broad bean, lentil and walnuts had the highest antioxidant capacity, whereas chickpeas, pine nuts and peanuts were less effective. The contribution of bound phytochemicals to the overall TAC was relevant in cereals as well as in nuts and pulses. The complete TAC database could be utilized to properly investigate the role of dietary antioxidants in disease prevention.     

Proximate composition,mineral and amino acid content of mature Canavalia gladiata seeds

The chemical composition and the nutritional quality of protein and carbohydrates of mature seeds of Canavalia gladiata (L.) were investigated. The whole and cotyledon flour of mature seeds contained; crude protein 26.8 and 29.2%; fat 2.8 and 3.1%; fibre 33.2 and 10.2%; ash 3.9 and 4.3%; carbohydrate 33.3 and 53.2% on dry matter basis respectively. The carbohydrate fractions have starch contents of 30.7 and 39.6% and 27.7 and 34.6 mg g⁻¹ low molecular weight carbohydrates on dry matter basis. The energy content of whole seed and cotyledon flour was 11,082 and 14,923 kJ kg⁻¹. Sucrose represents the highest fraction of low molecular weight carbohydrates with fructose being the lowest. The mineral analysis showed K, Mg, Ca, P and S to be present in high quantities. The essential amino acid profile compared well with FAO/WHO recommended pattern except for sulphur containing amino acids, cysteine and methionine. Therefore the chemical composition of the raw mature seeds of Canavalia gladiata (kernel) indicates the bean to be a good supplement to cereal-based diets.     

Determination of aflatoxin levels in nuts and their products consumed in South Korea

A total of 85 nuts and their products marketed in South Korea were assessed for aflatoxins using a monitoring scheme consisting of enzyme-linked immunosorbent assay (ELISA) for rapid screening, high performance liquid chromatography (HPLC) for quantification and LC–mass spectrometry (MS) for confirmation. Thirty-one out of 85 samples gave ELISA readings above 0.06 and were screened as possible positive samples. Aflatoxin contents of possible positive samples were determined using HPLC with a detection limit of 0.08–1.25 μg/kg and a quantification limit of 0.15–2.50 μg/kg. Nine samples including 1 raw peanut, 4 roasted peanuts, 2 peanut butters, 1 pistachio and 1 seasoned assorted nut were contaminated with aflatoxins (10.6% of incidence), ranging in various levels up to 28.2 μg/kg. LC–MS analysis on contaminated samples revealed that peaks eluting at 4.4, 5.2, 9.1 and 11.9 min were confirmed as aflatoxin G₁, aflatoxin B₁, aflatoxin G₂ and aflatoxin B₂, respectively.     

扁桃种仁氨基酸组分及加工品质分析

氧化程度对巴旦木营养和品质具有重要的影响,本研究的目的是建立一种灵敏、可靠的巴旦木氧化程度快速检测方法。本研究首先通过表面配体交换的转相策略实现了水溶液中分散的金纳米粒子（AuNPs）快速、简便地向非极性的甲苯溶液中的转相。UV-Vis和透射电镜等表征结果表明转相后的AuNPs的纳米形貌未发生明显的变化,可成功作为表面增强拉曼光谱（SERS）基底用于巴旦木油脂氧化程度的检测。结果表明,巴旦木油脂位于1655 cm⁻¹处的顺式双键的特征拉曼信号在氧化过程中逐渐减弱;选择酯键的1747 cm⁻¹作为参比信号,其特征峰的相对强度I₁₆₅₅/I₁₇₄₇值与巴旦木的加速氧化时间呈良好线性关系（R²=0.98）,SERS光谱结果结合主成分分析法可以用于实际巴旦木样品氧化程度的快速判定和分类。同时本研究也为适用于非水相食品中的SERS基底的制备和应用提供了新的思路。

     

Discoloration in raw and processed fruits and vegetables

Discoloration in fruits and vegetables is reviewed in relation to the chemical and biochemical causes of black, brown, red, yellow, and green discolorations. In raw materials, only a limited understanding has so far been achieved of the internal black and brown discolorations. The biochemical signaling pathways triggered by wounding or chilling-storage, the nature of the enzymes and reactive oxygen species involved, and the identity of the phenolic compounds oxidized are areas where further information is desirable. In processed materials, a greater comprehension is needed of the role of ascorbic acid reactions in the browning of fruits and "pinking" of Brassicaceous vegetables, and more information is desirable on the structure and properties of the discoloring pigments in many products. It is concluded that a greater knowledge of these areas, and of the naturally-occurring constituents that can accelerate or inhibit the causative reactions, would lead to the development of more efficient methods of controlling fruit and vegetable discolorations.     

超高效液相色谱—串联质谱法测定炒货中纽甜含量的不确定度评定

建立了一种测定炒货中纽甜含量的不确定度数学模型,分析了整个检测过程中各种不确定度影响因子并进行评定,确定有关分量并合成不确定度。结果表明,当样品中纽甜含量为7.69 mg/kg时,其扩展不确定度为0.71mg/kg(k=2),其中标准储备溶液的配制和测量重复性引入的不确定度影响较大。     

Antioxidant activities of some dried fruits consumed in Algeria

Dried fruits such as prune, apricots, raisins and figs are an important source of different antioxidants which can inhibit the harmful effects of the free radicals. They receive increasing attention for their potential role in prevention of human diseases. The aims of our study were the quantification of some antioxidants (carotenoïds, total phenolic compounds, anthocyanins, flavonoïds and proanthocyanidins) using colorimetric assays and the determination of antioxidant activities by three methods. Three aqueous solvents (distilled water, ethanol and methanol) were used for the extraction of some antioxidants. Apricots and figs had the highest concentration of carotenoïds (10.7 and 10.8 mg βCE/100 g, respectively). Raisins were the richest fruits in total phenolic concentration (1.18 g GAE/100 g) and proanthocyanidins (17.53 mg CE/100 g). Also, figs had the highest concentration of flavonoïds (105.6 mg QE/100 g) and anthocyanins (5.9 mg/100 g). Apricots and raisins possessed a good reducing power, while Agen prune showed significant antioxidant activity to the phosphomolybdate. There were significant correlations between total phenolic concentration and antiradical activity (r = 0.89; p < 0.001) of ethanolic extract and reducing power (r = 0.80; p < 0.01) of aqueous extract.     

Predominant mycobiota and aflatoxin content in Brazil nuts

The Brazil nut (Bertholletia excelsa) is an economically important product to the Brazilian Amazon. Currently, its marketing is being affected by the high incidence of aflatoxins (AF) produced by potentially aflatoxigenic fungi associated with its seeds. In this context, the purpose of this study was to determine which part of the nut contributes to contamination by aflatoxins and to identify the mycobiota in Brazil nut samples. Unshelled and shelled nuts were analyzed by measuring the total count of filamentous fungi (Aspergillus sections Flavi, Nigri and Circumdati) in sanitised and non-sanitised treatments. The isolates identified as Aspergillus section Flavi, the major producers of AF, were plated for determination of their aflatoxigenic potential. To perform the AF analysis, samples of Brazil nuts were treated separately. The AF from the shell and kernel were extracted by chloroform and analysed by the HPLC-FD system in isocratic mode. The Aspergillus section Flavi count was 21.67% lower. The production of AF by the isolated fungi was 30% for sanitised and 23.8% for non-sanitised samples. The concentrations obtained of AFB₁ and AFG₁ were higher than those of AFB₂ and AFG₂. The AFB₁ concentrations of shelled nuts and shell samples were 35.0 and 1.78 μg/kg, respectively. AFB₂ and AFG₂ were detected only in shelled nut samples. The HPLC-FD analysis presented limits of detection (LOD) and quantification (LOQ) of 0.2 and 0.4 μg/kg, respectively.     

Predominant mycobiota and aflatoxin content in Brazil nuts

The Brazil nut (Bertholletia excelsa) is an economically important product to the Brazilian Amazon. Currently, its marketing is being affected by the high incidence of aflatoxins (AF) produced by potentially aflatoxigenic fungi associated with its seeds. In this context, the purpose of this study was to determine which part of the nut contributes to contamination by aflatoxins and to identify the mycobiota in Brazil nut samples. Unshelled and shelled nuts were analyzed by measuring the total count of filamentous fungi (Aspergillus sections Flavi, Nigri and Circumdati) in sanitised and non-sanitised treatments. The isolates identified as Aspergillus section Flavi, the major producers of AF, were plated for determination of their aflatoxigenic potential. To perform the AF analysis, samples of Brazil nuts were treated separately. The AF from the shell and kernel were extracted by chloroform and analysed by the HPLC-FD system in isocratic mode. The Aspergillus section Flavi count was 21.67% lower. The production of AF by the isolated fungi was 30% for sanitised and 23.8% for non-sanitised samples. The concentrations obtained of AFB₁ and AFG₁ were higher than those of AFB₂ and AFG₂. The AFB₁ concentrations of shelled nuts and shell samples were 35.0 and 1.78???g/kg, respectively. AFB₂ and AFG₂ were detected only in shelled nut samples. The HPLC-FD analysis presented limits of detection (LOD) and quantification (LOQ) of 0.2 and 0.4???g/kg, respectively.     

Antioxidant activity of fresh and dry fruits commonly consumed in India

Epidemiological studies from other parts of the world indicate that increased consumption of fruits and vegetables are associated with lower risk of chronic degenerative diseases. Fruits are an important component of Indian diets. Studies indicate that fruits and vegetables are rich sources of phenolic compounds and antioxidant activity (AOA). Present study was taken up to determine the AOA and phenolic content of fresh and dry fruits commonly consumed in India by two different (radical scavenging) methods and relate it to their total phenolic content (TPC) for the first time. Fourteen commonly consumed fresh fruits and ten dry fruits were studied. AOA and TPC contents of both fresh and dry fruits showed marked variation. Correlation analysis between the TPC and AOA as assessed by the two methods showed that phenolics may contribute maximally to the ABTS (r = 0.84) and to lesser extent to DPPH (r = 0.77) in fresh fruits, where as in dry fruits they correlated well to DPPH activity (r = 0.97) and to a lesser extent to FRAP (r = 0.87). In general, the results indicate that majority of the fresh and dry fruits studied are rich in phenolic antioxidants with potent free radical scavenging activity imply their importance to human health.     

Antioxidant,toxicity, and iridoid tests of processed Cornelian cherry fruits

The antioxidant activity, potential toxicity, and iridoid content of processed Cornelian cherry products were assessed. Cornus officinalis L. juice and Cornus mas L. fruit puree possessed antioxidant activity in the 2,2‐diphenylpicrylhydrazyl radical scavenging, reducing power and oxygen radical absorbance capacity assays. Both products were non‐genotoxic in reverse mutation tests in Salmonella typhimurium. Both C. officinalis juice and C. mas puree were non‐toxic in acute oral toxicity tests, with respective LD₅₀ values >5100 mg kg^?1 body weight (b.w.) and >5200 mg kg^?1 b.w. The major iridoid identified in C. mas puree was loganic acid, while the major iridoid in C. officinalis juice was found to be morroniside. The presence of iridoids in C. mas is reported for the first time.     

Chemometric evaluation of trace metal concentrations in some nuts and seeds

Seventeen trace metals in acid digests of nuts and seeds were determined using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry. The data were subjected to chemometric evaluation using principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) in an attempt to classify the samples. Hazelnuts (raw and dry roasted), almonds (raw and dry roasted), sunflower seeds (black and white), peanuts (raw and dry roasted), cashew nuts, Brazil nuts, walnuts, chickpeas (raw and dry roasted), pumpkin seeds (raw and dry roasted), and pistachio nuts were used as samples. The samples were classified into seven groups by PCA and CA. All group members determined using PCA and CA were found by LDA to be correctly classified in the predicted groups. Interestingly, the chemometric evaluation indicated that the raw and roasted nuts are very close to each other even though some originated from different countries.     

Ultrasound decontamination of minimally processed fruits and vegetables

The effectiveness of power ultrasound for the microbial decontamination of minimally processed fruits and vegetables was studied. Reductions in Salmonella typhimurium attached to iceberg lettuce obtained by cleaning with water, chlorinated water, ultrasound with water and ultrasound with chlorinated water were 0.7, 1.7, 1.5 and 2.7 logs, respectively, for small-scale (2 L) trials. The cleaning action of cavitation appears to remove cells attached to the surface of fresh produce, rendering the pathogens more susceptible to the sanitizer. For large-scale (40 L) trials, the addition of chlorine to water in the tank gave a systematic difference in Escherichia coli decontamination efficiency. However, the frequency of ultrasound treatment (25, 32–40, 62–70 kHz) had no significant effect on decontamination efficiency ( P  > 0.69). With the potentially high capital expenditure together with the expensive process of optimization and water treatment, it is unlikely that the fresh produce industry would be willing to take up this technology. Furthermore, the additional one log reduction achieved by applying ultrasound to a chlorinated water wash does not completely eliminate the risk of pathogens on fresh produce.