玉米籽粒发芽过程中不同部位类胡萝卜素合成动态及抗氧化活性

本研究以黄玉米种子为原料,研究其在发芽过程中种胚、胚芽和胚根中总类胡萝卜素、叶黄素和玉米黄质的合成动态以及抗氧化活性。结果表明:玉米籽粒的发芽率随着发芽时间的延长而增加,在12～36 h间是玉米籽粒的出芽时间。玉米籽粒发芽过程中种胚、胚根和胚芽的鲜重呈现上升趋势,且种胚鲜重胚芽鲜重胚根鲜重。随着发芽时间的增加,种胚和胚根的总类胡萝卜素积累量增加,而胚芽中的总类胡萝卜素积在36～48 h和60～72 h增加极为显著。种胚、胚根和胚芽中主要类胡萝卜素物质以叶黄素为主,胚芽的总类胡萝卜素含量明显高于胚根和种胚。玉米籽粒发芽72 h时总类胡萝卜素含量为发芽前的6.19倍。同时,胚芽和种胚中的抗氧化活性随着发芽时间的增加而升高,最高分别达到了8.01μmol TEAC/g和8.51μmol TEAC/g,胚根则相反。故发芽可以显著提高玉米籽粒中不同部位的类胡萝卜素含量及胚芽的抗氧化活性。     

食用木薯块根及其制品中生氰糖苷检测方法的建立与应用

生氰糖苷含量的高低对评估食用木薯块根及其制品的食用安全性及其重要。以木薯块根和木薯粉为试材,本研究建立了亚麻苦苷和百脉根苷2种生氰糖苷（Cyanogenic Glycosides,CNGs）的快速提取和高效液相色谱-蒸发光散射（HPLC-ELSD）检测的方法,分析了不同品种木薯块根、木薯粉及其制品中CNGs含量变化。结果表明,食用木薯块根及木薯粉中CNGs提取最佳的硫酸溶液浓度分别为0.025和0.100 mol/L;HPLC-ELSD检测方法可有效分离亚麻苦苷和百脉根苷,其浓度在4.1～820.0 mg/L和2.5～250.0 mg/L范围内线性相关性较好,相关系数（r）分别达到了0.9996和0.9993,检测限（LOD）分别为2.1和0.5 mg/kg,定量限（LOQ）分别为8.2和2.0 mg/kg;该方法重复性和样品稳定性的标准偏差（RSD）都低于5.0%;木薯块根和木薯粉中2种CNGs的平均加标回收率分别在89.3%～96.3%和107.5%～114.9%之间,重复间RSD小于3.4%。样品验证结果表明:不同的木薯品种CNGs含量差异较大;种植8～9个月的木薯制备木薯粉CNGs含量较低;蒸煮加工方式可有效清除木薯食品中CNGs。本方法操作简单、稳定性较好、准确度高,在食用木薯块根及其制品中CNGs的分析与评价等研究方面具有较强的应用前景。     

Retention of Folate, Carotenoids, and Other Quality Characteristics in Commercially Packaged Fresh Spinach

ABSTRACT: The effect of storage temperature (4 °C, 10 °C, and 20 °C) on retention of folate, carotenoids, and other quality characteristics in commercially packaged fresh spinach were determined. Based on visual color and appearance, spinach was unacceptable after 8 d, 6 d, and 4 d at 4 °C, 10 °C, and 20 °C, respectively. Color differences (AE), chlorophyll degradation, fresh weight loss, and microbial populations increased at all storage temperatures and occurred more rapidly at higher temperatures. Peroxidase activity increased but was not significantly ( P > 0.05) affected by storage temperature. Lipoxygenase activity was unaffected by storage time or temperature. Substantial losses of nutrients occurred at each storage temperature. Only 53% of folate in packaged spinach was retained after 8 d, 6 d, and 4 d at 4 °C, 10 °C, and 20 °C, respectively. Carotenoid losses increased with temperature with only 54%, 61%, and 44%, respectively, of initial detected levels remaining. Vitamin and quality changes were unaffected by presence or absence of packaging.     

木薯代替玉米对鹅饲养效果的研究

选择28日龄四川白鹅96只,随机分为4个组,每组3个重复,每个重复8只,进行为期42 d的饲养试验.结果表明:玉米组、木薯替代35%玉米饲粮组、木薯替代55%玉米饲粮组、木薯替代75%玉米饲粮组,平均日增重分别为42.30、39.19、39.38和39.82 g,但组间差异不显著(P＞0.05);各组鹅的胴体肉用性能指标无明显差异(P＞0.05);用木薯饲粮喂鹅会造成经济效益不同程度的下降.     

Carotenoids in cassava: Comparison of open-column and HPLC methods of analysis

Cassava leaves and tubers from six cultivars were analysed for carotenoids by both open-column chromatography and high-performance liquid chromatography (HPLC). The major carotenoids of leaves were the non-vitamin A carotenoid lutein (86-290 mg kg^?1 fresh weight (FW)) and the pro-vitamin A carotenoid β-carotene (13-78 mg kg^?1 FW). Immature leaves contained less than mature leaves. Tubers contained 0.1-3 mg kg^?1 FW of β-carotene and 0.05-0.6 mg kg^?1 FW of lutein. Carotenoids present in small amounts included α-, γ-, and §-carotenes and β-cryptoxanthin and others were separated and partially identified. Yellow tubers contain much more β-carotene than white tubers and cassava is a good source of pro-vitamin A carotenoids compared with other root crops. Both methods gave similar results for β-carotene and lutein, but the open-column method did not allow separation and quantitation of carotenoids present in small amounts. HPLC separated many carotenoids, but most peaks could not be identified for lack of reference compounds. A great advantage of open-column chromatography for developing countries is its use of simple equipment and readily available reagents and solvents compared with HPLC, which requires complex equipment needing careful maintenance and expensive solvents. The open-column method is more labour intensive but this is not a constraint in developing countries.     

黄玉米粗类黄酮提取工艺正交试验优化及其体外抗氧化活性

以黄玉米纪元1号为材料,采用单因素试验与三元二次正交试验,考察乙醇体积分数、料液比、浸提温度及浸提时间对粗类黄酮提取量的影响及黄玉米粗类黄酮清除1,1-二苯基-2-苦肼基（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基和•OH的能力。得出最优工艺参数为料液比1∶35.5（g/mL）、69 ℃浸提1.85 h,此条件下粗类黄酮提取量为85.88 mg/g。当粗类黄酮质量浓度为20 mg/mL时,对DPPH自由基和•OH的清除率分别为76.47%和32.62%,分别相当于芦丁标准品（0.1、0.2 mg/mL）清除能力的81%～84%和40%～50%。黄玉米粗类黄酮对DPPH自由基的清除率明显大于对• OH的清除率,且随质量浓度提高,清除率显著提高（P＜0.05）。     

Cassava varietal screening for cooking quality: Relationship between dry matter,starch content,mealiness and certain microscopic observations of the raw and cooked tuber

Thirteen cassava (Manihot esculenta L Crantz) varieties from three successive annual harvests were screened for the mealiness of the cooked tuber, and the elasticity and smoothness of the pounded paste. Six were selected for further studies based on their mealiness and the starch and dry matter contents were determined. The diameter of the starch granules of the selected varieties and those of an irradiated M₁ V₂ population were measured. Microscopic examinations of the raw and cooked cells of the irradiated M₁ V₂ population were made. Correlations among all the parameters were studied. Varietal and seasonal differences in cooking quality were observed. There was no consistent relationship between mealiness of the boiled tuber and the elasticity and smoothness of the pounded paste. Varieties that were mealy were high in dry matter and starch content. The starch granules of mealy varieties were larger than those of nonmealy ones. There were no differences between mealy and non-mealy varieties in the arrangement of the cells or ‘cell condition’, of the raw tubers. However, the cells of the cooked tubers were held less cohesively, ie there was more ‘cell disorganisation’, in mealy varieties than in non-mealy ones.     

Visual Performance in the “Real World”: Contrast Sensitivity,Visual Acuity,and Effects of Macular Carotenoids

Visual acuity (VA) is compared to contrast sensitivity (CS) testing in assessing “real‐world” visual performance, and it is recommended that both should be measured routinely in the clinic. The role of nutritional intervention in improving visual performance is reviewed and emphasized. A brief history and illustration of both VA and CS, within the scope of visual performance, is presented. Parameters for effective CS testing in the clinic, and guidelines for interpretation of results, including a new model for understanding the visual impact of changes in CS, are also presented. Relevant research that supports the use of the macular carotenoids lutein, zeaxanthin, and meso‐zeaxanthin to enhance visual performance is reviewed with suggested guidelines for supplementation. CS testing is easily performed at a single intermediate target size and is an excellent tool for the accurate assessment of a patient's overall visual experience. Research continues to uncover the strong link between nutrition and visual performance; the macular carotenoids appear to be especially effective in this regard, and their benefits to visual performance now importantly include contrast sensitivity. Clinicians can provide an improved level of care by incorporating into the examination protocol CS testing and, where appropriate, nutritional counseling and intervention.     

Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth,development and iodine uptake of lettuce grown in water culture

BACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. RESULTS: In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 µg iodine L^?1, applied as iodate (IO₃^?) or iodide (I^?), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I^? than with IO₃^?. Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 µg iodine kg^?1 total leaf fresh weight. CONCLUSION: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I^? and IO₃^?. I^? was more effective than IO₃^?. Fifty grams of iodine‐biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. Copyright © 2010 Society of Chemical Industry     

Effect of Non-Ionic Surfactants and Beta-Ionone on the Morphology of Blakeslea trispora and Carotenoids Production from Cheese Whey in Submerged Aerobic Growth: A Statistical Approach

The effect of non-ionic surfactants and β-ionone on morphology of Blakeslea trispora and carotenoids production from deproteinized hydrolyzed whey in submerged aerobic growth was investigated. Also, a central composite design was employed to determine the maximum carotenoids concentration at optimum values for the process variables (Tween 80, Span 80, β-ionone). The fit of the model was found to be good. Tween 80 and Span 80 had a strong linear effect on carotenoids production. The concentration of carotenoids was significantly affected by Tween 80 – Span 80 and Span 80 – β-ionone interactions as well as by the negative quadratic effect of β-ionone. The optimum medium composition for the maximum carotenoids production (100.0 ± 5.0 mg/g biomass dry weight) was found in deproteinized hydrolyzed whey supplemented with Tween 80 (33.6 g/L), Span 80 (68.7 g/L), and β-ionone (2.6 g/L). This result indicated that the optimization strategy led to an increase in carotenoids production by 33-fold. The carotenoids content in B. trispora were β-carotene, γ-carotene, and lycopene. The composition of carotenoids depends of the amount of nonionic surfactants and β-ionone added to the cheese whey. The medium composition influenced the morphogenesis of B. trispora and product formation. The addition of surfactants into the medium changed the morphology of the microorganism from solid aggregates to loose aggregates and resulted in a substantial increase in pigment production. B. trispora growing in submerged aerobic growth is able to develop complex morphologies which have been classified into three major groups: freely dispersed hyphae, clumps, and pellets. These parameters are responsible for the production of carotenoids.     

A review of root,tuber and banana crops in developing countries: past,present and future

For many of the developing world's poorest farmers and food-insecure people, roots, tubers, bananas and plantain crops (RTBs) serve as a critical source of food, nutrition and cash income. RTBs have been particularly important in areas where local agri-food systems are under stress. Under such circumstances, growers, processors and traders often see opportunities to improve food security or increase their incomes with those crops due to shifting tastes and preferences for food and non-food products. Since the early 1990s, cassava output surged in sub-Saharan Africa, while potato production expanded rapidly in Asia. RTBs are consumed by over three billion people in developing countries with a market value of US$ 339 billion. This paper analyses the major changes in production, utilisation and trade of RTBs over the last six decades, assesses estimates of their future trajectory and offers recommendations so that they might achieve their full potential.     

A review of varietal change in roots,tubers and bananas: consumer preferences and other drivers of adoption and implications for breeding

This review of the literature on varietal change in sub-Saharan Africa looks in detail at adoption of new varieties of bananas in Uganda, cassava in Nigeria, potato in Kenya, sweetpotato in Uganda and yams in Côte d’Ivoire. The review explored three hypotheses about drivers of varietal change. There was a strong confirmation for the hypothesis that insufficient priority given to consumer-preferred traits by breeding programmes contributes to the limited uptake of modern varieties (MVs) and low varietal turnover. Lack of evidence meant the second hypothesis of insufficient attention to understanding and responding to gender differences in consumer preferences for quality and post-harvest traits was unresolved. The evidence on the third hypothesis about the informal seed system contributing to slow uptake of MVs was mixed. In some cases, the informal system has contributed to rapid uptake of MVs, but often it appears to be a barrier with inconsistent varietal naming a major challenge.     

Postharvest processes of edible insects in Africa: A review of processing methods,and the implications for nutrition,safety and new products development

In many African cultures, insects are part of the diet of humans and domesticated animals. Compared to conventional food and feed sources, insects have been associated with a low ecological foot print because fewer natural resources are required for their production. To this end, the Food and Agriculture Organization of the United Nations recognized the role that edible insects can play in improving global food and nutrition security; processing technologies, as well as packaging and storage techniques that improve shelf-life were identified as being crucial. However, knowledge of these aspects in light of nutritional value, safety, and functionality is fragmentary and needs to be consolidated. This review attempts to contribute to this effort by evaluating the available evidence on postharvest processes for edible insects in Africa, with the aim of identifying areas that need research impetus. It further draws attention to potential postharvest technology options for overcoming hurdles associated with utilization of insects for food and feed. A greater research thrust is needed in processing and this can build on traditional knowledge. The focus should be to establish optimal techniques that improve presentation, quality and safety of products, and open possibilities to diversify use of edible insects for other benefits.     

A wild strain of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) from farm-stored maize in South Carolina: Effect of temperature on mating, survival, and fecundity

The purpose of this study was to develop age-specific survivorship and fecundity schedules for adult Plodia interpunctella (Hübner) relevant to maize storages, with special reference to the southeastern states (USA). Laboratory cultures were established with moths collected from farm-stored maize in South Carolina and maintained on cracked maize at 30 °C and 60% r.h. Age-specific schedules of survivorship and fecundity, the length of the oviposition period, mating success, and mating frequency were determined at 20, 25, 30, and 35 °C and about 75% r.h. The maximum oviposition period was longest (18 d) at 20 and 25 °C, and shortest (8 d) at 35 °C. The optimum temperatures for reproduction (mating frequency and fecundity) were 25–30 °C, but mean life-span was longest (13.2 d) at 20 °C and declined linearly with increasing temperature. Mean total (lifetime) fecundity ranged from 16.9 eggs at 35 °C to 227.7 eggs at 25 °C.     

A wild strain of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) from farm-stored maize in South Carolina: Development under different temperature, moisture, and dietary conditions

The purpose of this study was to determine the duration of immature development and survivorship of Plodia interpunctella (Hübner) on maize over a range of temperatures and grain moisture contents encountered in maize stored on farms in the southeastern states (USA). Laboratory cultures were established with moths collected from farm-stored maize in South Carolina and maintained on cracked maize at 30 °C and 60% r.h. The incubation period and percentage hatch of eggs was determined at 18 combinations of temperature and r.h. Hatch was <1% at 15 and 40 °C. In the range 20-35 °C, percentage hatch declined as temperature increased, and the mean incubation period ranged from 3.1 to 8.5 d. Neither percentage hatch nor incubation period were affected by r.h. between 43% and 76%. The relationship between mean developmental period (oviposition to adult eclosion) and temperature was well described by a quadratic polynomial that predicted a decline from 67.6 to 30.1 d as temperature increased from 20 to 31.1 °C, followed by an increase to 38.5 d as temperature increased further to 35 °C. The results suggest a lower temperature threshold for development near 15 °C and an upper limit slightly greater than 35 °C. Moisture content had a significant effect on developmental period at all the temperatures studied, but the pattern of variation with moisture depended upon the temperature.     

The Bioaccumulation and Physiological Effects of Heavy Metals in Carrots,Onions, and Potatoes and Dietary Implications for Cr and Ni: A Review

The bioaccumulation of heavy metals in food tubers (carrots, onions, and potatoes) as a result of polluted irrigation water has been studied in this review paper. Given that heavy metals can cause a considerable oxidative stress, the impact of these metals to the physiology of the plants has also been assessed. The consumption of vegetables cross‐contaminated with heavy metals carries a considerable risk for humans (especially for children and pregnant women) and these dietary implications are discussed while European Food Safety Authority has been urged to look into this matter of concern.     

Formation,nutritional value,and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans

Black garlic (BG) is essentially a processed food and obtained through the transformation of fresh garlic (FG) (Allium sativum L.) via a range of chemical reactions (including the Maillard reaction) and microbial fermentation. This review provides the up‐to‐date knowledge of the dynamic and complicated changes in major components during the conversion of FG to BG, including moisture, lipids, carbohydrates (such as sugars), proteins, organic acids, organic sulfur compounds, alkaloids, polyphenols, melanoidins, 5‐hydroxymethylfurfural, vitamins, minerals, enzymes, and garlic endophytes. The obtained evidence confirms that BG has several advantages over FG in certain product attributes and biological properties (especially antioxidant activity), and the factors affecting the quality of BG include the type and characteristics of FG and processing technologies and methods (especially pretreatments, and processing temperature and humidity). The interactions among garlic components, and between garlic nutrients and microbes, as well as the interplay between pretreatment and main manufacturing process, all determine the sensory and nutritional qualities of BG. Before BG is marketed as a novel snack or functional food, more research is required to fill the knowledge gaps related to quantitative monitoring of the changes in metabolites (especially those taste‐active and/or biological‐active substances) during BG manufacturing to maximize BG's antioxidant, anticancer, antiobesity, anti‐inflammatory, immunostimulatory, anti‐allergic, hepatoprotective, cardioprotective and oxidative stress‐/hangover syndrome‐reducing functions, and beneficial effects on memory/nervous systems. Assessments of the quality, efficacy, and safety of BG should be performed considering the impacts of BG production conditions, postproduction handling, and intake methods.     

Understanding the Relations Among the Storage,Soaking, and Cooking Behavior of Pulses: A Scientific Basis for Innovations in Sustainable Foods for the Future

The world faces challenges that require sustainable solutions: food and nutrition insecurity; replacement of animal‐based protein sources; and increasing demand for convenient, nutritious, and health‐beneficial foods; as well as functional ingredients. The irrefutable potential of pulses as future sustainable food systems is undermined by the hardening phenomenon that develops upon their storage under adverse conditions of temperature and relative humidity. Occurrence of this phenomenon indicates storage instability. In this review, the application of a material science approach, in particular the glass transition temperature concept, is presented to explain phenomena of storage instability such as the occurrence of hardening and loss of viability under adverse storage conditions. In addition to storage (in)stability, application of this concept during processing of pulses is discussed. The state‐of‐the‐art on how hardening occurs, that is, mechanistic insights, is provided, including a critical evaluation of some of the existing postulations using recent research findings. Moreover, the influence of hardening on the properties and processing of pulses is included. Prevention of hardening and curative actions for pulses affected by the hardening phenomenon are described in addition to the current trends on uses of pulses and pulse‐derived products. Based on the knowledge progress presented in this review, suggestions for the future include: first, the need for innovation toward implementation of recommended solutions for the prevention of hardening; second, the optimization of the identified most effective and efficient curative action against hardening; and third, areas to focus on for elucidation of mechanisms of hardening, although existing analytical methods require advancement.