Folate content in strawberries (Fragaria x ananassa): effects of cultivar,ripeness, year of harvest,storage, and commercial processing

Folate concentrations in strawberries and folate retention during storage and commercial processing of strawberries were investigated. No previous study has focused on the effects of cultivar, ripeness, and year of harvest of strawberries with respect to the folate content. This study showed the folate concentration in strawberries to significantly depend on all of these different factors. Total folate was quantified using a modified and validated radioprotein-binding assay with external calibration (5-CH(3)-H(4)folate). Folate content in 13 different strawberry cultivars varied from 335 microg/100 g of dry matter (DM) for cv. Senga Sengana to 644 microg/100 g of DM for cv. Elsanta. Swedish harvests from 1999 and 2001 yielded higher folate concentrations than did the harvest from 2000, and the grade of ripeness affected the folate content in strawberries. This study indicated high folate retention in intact berries during storage until 3 or 9 days at 4 degrees C (71-99%) and also in most tested commercial products (79-103%). On the basis of these data fresh strawberries as well as processed strawberry products are recommended to be good folate sources. For instance, 250 g (fresh weight) of strawberries ( approximately 125 microg of folate) supplies approximately 50% of the recommended daily folate intake in various European countries (200-300 microg/day) or 30% of the U.S. recommendation (400 microg/day).     

Composition,Nutritional Value,Functionality, Processing,and Novel Food Uses of Pulses and Pulse Ingredients

Pulses, the dry edible seeds of plants in the legume family, include field pea, dry bean, lentil, chickpea, and fababean. The contemporary definition of pulses excludes oilseed legumes and legumes consumed in immature form. Pulses have been nourishing people around the world for thousands of years and are well known as a rich, sustainable source of protein that is high in lysine and therefore complementary to protein from cereals. They also are good sources of energy and dietary fiber, are low in fat, and contain significant levels of vitamins, minerals, and other micronutrients and bioactives. Owing to its intermediate amylose content, starch from pulses is digested more slowly than are most cereal and tuber starches. Whole and split pulses and pulse flours also exhibit relatively high levels of type 1 resistant starch. As a result, the consumption of pulses is beneficial to the management of type 2 diabetes, metabolic syndrome, and obesity, is associated with a reduced risk of cardiovascular disease and cancer, and contributes to overall health and wellness. Pulses are used in whole or dehulled form in canned goods, sweets, soups, and pastes, whereas pulse flours are becoming common ingredients in a wide variety of food and pet food products such as baked goods, pasta and noodles, biscuits, and condiments. There is considerable interest currently in dry and wet fractionation of pulses into starch, protein, and fiber concentrates for use in both food and nonfood applications. As consumers are becoming increasingly health conscious and focused on a wellness‐oriented lifestyle, they are demanding tasty and convenient food products that are plant‐based and provide both nutritional and health benefits. In recent years, interest in the use of pulses and their ingredients in food formulation has grown tremendously owing to their nutritional and health benefits and unique functionality, a rise in the incidence of food allergies, and the availability of novel processing technologies. The United Nations declared 2016 as the International Year of Pulses, which was celebrated through the hosting of scientific and educational activities worldwide, all aimed at increasing consumer awareness of the benefits of pulse consumption and of the role of pulses in sustainable crop production systems. The ultimate goal was increased production and consumption of pulses in both developed and developing countries. This focus issue of Cereal Chemistry captures current research related to pulse composition, processing technologies, nutritional and functional attributes of pulse ingredients, impacts of processing on composition and functionality, potential health benefits, and novel food applications. It also includes review articles on composition, nutritional value and health benefits, traditional and new food uses, determination of protein nutritional quality, evaluation of cooking time, effects of processing on antinutrients, and flavor aspects of ingredients.     

Composition,Nutritional Value,and Health Benefits of Pulses

The United Nations has declared 2016 as the International Year of Pulses. Pulses are narrowly defined as leguminous crops that are harvested as dry seeds. Although some pulse crops are harvested green (e.g., green peas), these are classified as vegetables because the pods are often consumed along with the mature and sometimes immature seeds. Other dried legumes such as soybean and peanut meet the definition of being a leguminous crop that is harvested as dry seeds; however, these crops are grown primarily for oil content and, thus, are not categorized as pulses. There are hundreds of pulse varieties grown worldwide; these include, for example, dry edible beans, chickpeas, cowpeas, and lentils. This review will cover the proximate (e.g., protein, carbohydrates, vitamins, and minerals), and phytonutrient (e.g., polyphenolics and carotenoid) composition of dry edible beans, peas, lentils, and chickpeas. Soybean and peanuts will not be covered in this review. The effects of processing on composition will also be covered. The health benefits related to folates, fiber, and polyphenolics will be highlighted. The health benefits discussed will include cardiovascular disease, cancer, diabetes, and weight control. The current review will not cover antinutrient compounds; this topic will be covered in a separate review article published in the same issue.     

Effect of germination and thermal treatments on folates in rye

Effects of germination conditions and thermal processes on folate contents of rye were investigated. Total folate contents were determined microbiologically with Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism, and individual folates were determined by high-performance liquid chromatography after affinity chromatographic purification. Germination increased the folate content by 1.7-3.8-fold, depending on germination temperature, with a maximum content of 250 micro g/100 g dry matter. Hypocotylar roots with their notably high folate concentrations (600-1180 micro g/100 g dry matter) contributed 30-50% of the folate contents of germinated grains. Germination altered the proportions of folates, increasing the proportion of 5-methyltetrahydrofolate and decreasing the proportion of formylated folate compounds. Thermal treatments (extrusion, autoclaving and puffing, and IR and toasting) resulted in significant folate losses. However, folate levels in grains that were germinated and then were heat processed were higher than for native (nongerminated) grains. Opportunities to optimize rye processing to enhance folate levels in rye-based foods are discussed.     

Total folate content and retention in rosehips (Rosa ssp.) after drying

Folate concentrations in rosehips and commercial rosehip products and factors affecting folate retention during drying were investigated. On the basis of the raw material studied during 3 years, rosehips were shown to be a rich folate source, 400-600 microg/100 g based on dry matter and 160-185 microg/100 g based on the fresh weight (edible part). Rosehips are not often consumed fresh; therefore, drying to produce stable semimanufactures is a crucial step. The degradation of folate was shown to be dependent on the drying time until the water activity was below 0.75. The required drying time was reduced by cutting the rosehips in slices and to some extent also by increasing the temperature. Retention of folate and ascorbic acid was affected by the same factors, and high content of ascorbic acid could provide a possible protection for folate degradation.     

有机多肽酶活性促进剂施用方式对鲜食型甘薯干物质积累分配、产量及品质的影响

为探究有机多肽酶活性促进剂对鲜食型甘薯产量和品质的调控效应,在大田条件下,以鲜食型甘薯品种龙薯9号和苏薯8号为供试材料,每个品种设置全生育期不喷施有机多肽酶活性促进剂(CK)、有机多肽酶活性促进剂栽插前蘸根+栽后40 d叶面喷施(P1)和有机多肽酶活性促进剂栽插时灌根+栽后40 d叶面喷施(P2)3个处理,研究其对鲜食型品种干物质积累分配、产量及品质的影响。结果表明,2个品种的P1和P2处理生长中后期叶片的磷酸蔗糖合成酶(SPS)活性、蔗糖含量、收获期植株总干重和块根干重均显著高于CK。龙薯9号各处理收获期的侧枝茎和块根干物质分配比例均无显著差异,P1和P2处理的主茎下部叶、主茎下部茎干物质分配比例均显著低于CK;苏薯8号P2处理的主茎下部叶、主茎下部茎、侧枝茎和侧枝生长点干物质分配比例均显著低于CK和P1处理,块根干物质分配比例显著高于CK和P1,分别提高8.98%和6.23%。龙薯9号P2处理收获期块根可溶性糖含量与P1无显著差异,但显著低于CK,降低5.22%,P2处理的块根淀粉含量显著高于CK和P1,分别提高18.76%和9.23%,干率与P1处理无显著差异,但均显著高于CK,分别提高4.56%和5.71%;苏薯8号块根的可溶性糖含量各处理无显著差异,且P2处理的块根淀粉含量和干率与P1均无显著差异,但显著高于CK,其中淀粉含量提高6.13%,干率提高4.51%。2个品种P2处理的块根产量均显著高于CK和P1,其中龙薯9号分别提高30.46%和14.42%,苏薯8号分别提高27.72%和11.69%。综上,施用有机多肽酶活性促进剂有利于提高鲜食型品种块根产量和淀粉含量,其中P2处理增产幅度最高,其对可溶性糖含量的调控存在品种间差异。本研究为鲜食型甘薯提质增效和生态种植技术提供了理论依据。     

Cultivar and year-to-year variation of phytosterol content in rye (Secale cereale L.)

Intake of phytosterols (and -stanols) has been shown to decrease the level of low-density lipoprotein cholesterol and thus protect against development of cardiovascular diseases. Therefore, studies on the cultivar and year-to-year variation in phytosterol content in rye grains have been performed. The phytosterol content and composition of different rye cultivars, grown under identical conditions on the same field in three consecutive years, were analyzed. Both cultivar and year-to-year variation in sterol content were statistically significant (p < 0.0001). The total sterol content varied from 1007 +/- 21 mg/kg in the highest yielding cultivar, Tsulpan 3, to 761 +/- 10 mg/kg in the lowest yielding cultivar (Amando in the 1999 harvest). Because the meteorological conditions varied substantially between the different years, it was possible to deduce the impact of varying weather conditions on phytosterol content in the different cultivars. The studied cultivars had all the lowest phytosterol contents in the dry and warm harvest season of 1999. Although there were statistically significant cultivar and year-to-year variations in the sterol composition (p < 0.0001), these were only between 2 and 4% of the total sterol content.     

Factors Influencing Yeast Fermentation and the Effect of LMW Sugars and Yeast Fermentation on Hearth Bread Quality

The purpose of this study was to investigate how wheat cultivar, growth location, type of mill, LMW sugar composition of wheat flours, mixing time, and type of mixer affected yeast fermentation. Also studied was the effect of yeast fermentation and LMW sugar composition on hearth bread quality. To achieve this, 36 different flours were produced from two different mills using six different wheat cultivars grown at three locations. Yeast fermentation in doughs, measured as gas production, was determined using realtime pressure measurements and GasSmart software. A short mixograph mixing or spatula mixing was not efficient enough to rehydrate instant dry yeast. Compressed yeast and a short mixing time were enough to reach maximum fermentation rate. Maximum pressure after 210 min of fermentation was higher for instant dry yeast than for compressed yeast. Wheat cultivar and growth location had a significant effect on LMW sugar composition. Wheat cultivar, growth location, and type of mill used significantly affected pressure curve parameters. Oligosaccharides and damaged starch were positively correlated, and ash content and flour yield were negatively correlated with pressure curve parameters. Hearth bread characteristic crumb structure was positively correlated with all pressure curve characteristics except fast fermentation rate. Increased levels of mono‐ and disaccharides in wheat flour gave hearth breads with a more round shape.     

菠菜硝态氮累积和还原与植株生长的关系

通过盆栽试验,以两个硝态氮含量差异显著的菠菜品种为供试材料,在不同生长时期,测定了叶柄、叶片干重、水分含量、硝态氮含量及叶片内源和外源硝酸还原酶活性,研究菠菜硝态氮累积和硝酸还原酶活性的动态变化及其与植株生长变化的关系。结果表明,随生长期后移,叶柄、叶片及地上部干重和水分含量先增加而后降低,硝态氮含量则持续降低,低硝态氮累积品种S9的下降更为明显,出苗后52d和62d地上部分别降低了100%和89.7%;叶片内源和外源酶活性则随植株生长量增加而增加,高硝态氮累积品种S4增加（379%和199%）更明显,之后该品种酶活性随植株生长量降低而显著下降,品种S9却显著增加,分别为121%和288%。生长前期,品种S4硝态氮含量、干重增长速率及内源、外源酶活性均显著高于品种S9,内源/外源酶活性比值却明显低于后者;生长后期,除外源酶活性和内源/外源酶活性比值外,品种间差异均不明显。因此,生长前期高累积品种硝态氮含量降低较少,主要原因可能是其内源/外源酶活性比值（70.7%）较低,生长后期该品种的内源/外源酶活性比值（98.2%）显著增加后,硝态氮含量迅速下降进一步证明了这一推测。综合上述结果可知,内源/外源酶活性比值更能揭示植株生长变化引起的品种间硝态氮含量变化差异。     

Development of a simplified method for the determination of folates in baker's yeast by HPLC with ultraviolet and fluorescence detection

A simplified HPLC method for rapid determination of folates in yeast with ultraviolet and fluorescence detection without sample purification has been developed. By use of the column Aquasil C(18), specially designed for polar analytes, and gradient elution, it was possible to separate and determine five folate derivatives: tetrahydrofolate, 5-methyltetrahydrofolate, and 5-formyltetrahydrofolate with fluorescence detection, and 10-formylfolic acid and folic acid with ultraviolet detection. The sample preparation required only a small amount of dry yeast (25-50 mg) and included an extraction of folates by heat treatment and deconjugation of folate polyglutamates to monoglutamates with the use of rat serum conjugase. Validation involved investigation of matrix effects, determination of recovery by standard addition method, repeatability, and stability tests. The dominating folate forms in commercial dry baker's yeast were found to be tetrahydrafolate and 5-methyltetrahydrofolate with a total folate content of 2890 microg/100 g (63.4 nmol/g). The simplicity of the method makes it suitable for folate screening studies of different yeast strains.     

小麦品种的耐盐性变化：甜菜碱和乙烯的作用

Four wheat (Triticum aestivum L.) cultivars 711, PBW343, 3765 and WH542 were screened for studying variations in glycinebetaine (GB) content and plant dry mass under 100 mmol L-1 NaCl stress. A tolerance index was calculated using plant dry mass data to select salt-tolerant and salt-sensitive types and find association between tolerance index and GB content. Tolerance index has been used as a good criterion to select the tolerant types under high salinity stress. Further, physiological differences in salt-tolerant cultivar 711 and salt-sensitive cultivar WH542 were examined. The salt-tolerant cultivar exhibited greater GB content, which was found correlative with ethylene. The cultivar also showed higher nitrogen (N) content and nitrate reductase activity, reduced glutathione and higher redox state resulting in maximal protection of plant dry mass than the salt-sensitive type. Thus, the content of GB may be considered as important physiological criteria for selecting salt-tolerant wheat types.     

Carbon pulses but not phosphorus pulses are related to decreases in microbial biomass during repeated drying and rewetting of soils

Drying and rewetting cycles are known to be important for the turnover of carbon (C) in soil, but less is known about the turnover of phosphorus (P) and its relation to C cycling. In this study the effects of repeated drying-rewetting (DRW) cycles on phosphorus (P) and carbon (C) pulses and microbial biomass were investigated. Soil (Chromic Luvisol) was amended with different C substrates (glucose, cellulose, starch; 2.5 g C kg⁻¹) to manipulate the size and community composition of the microbial biomass, thereby altering P mineralisation and immobilisation and the forms and availability of P. Subsequently, soils were either subjected to three DRW cycles (1 week dry/1 week moist) or incubated at constant water content (70% water filled pore space). Rewetting dry soil always produced an immediate pulse in respiration, between 2 and 10 times the basal rates of the moist incubated controls, but respiration pulses decreased with consecutive DRW cycles. DRW increased total CO₂ production in glucose and starch amended and non-amended soils, but decreased it in cellulose amended soil. Large differences between the soils persisted when respiration was expressed per unit of microbial biomass. In all soils, a large reduction in microbial biomass (C and P) occurred after the first DRW event, and microbial C and P remained lower than in the moist control. Pulses in extractable organic C (EOC) after rewetting were related to changes in microbial C only during the first DRW cycle; EOC concentrations were similar in all soils despite large differences in microbial C and respiration rates. Up to 7 mg kg⁻¹ of resin extractable P (P_resin) was released after rewetting, representing a 35-40% increase in P availability. However, the pulse in P_resin had disappeared after 7 d of moist incubation. Unlike respiration and reductions in microbial P due to DRW, pulses in P_resin increased during subsequent DRW cycles, indicating that the source of the P pulse was probably not the microbial biomass. Microbial community composition as indicated by fatty acid methyl ester (FAME) analysis showed that in amended soils, DRW resulted in a reduction in fungi and an increase in Gram-positive bacteria. In contrast, the microbial community in the non-amended soil was not altered by DRW. The non-selective reduction in the microbial community in the non-amended soil suggests that indigenous microbial communities may be more resilient to DRW. In conclusion, DRW cycles result in C and P pulses and alter the microbial community composition. Carbon pulses but not phosphorus pulses are related to changes in microbial biomass. The transient pulses in available P could be important for P availability in soils under Mediterranean climates.     

Growth,yield and nutrient uptake of taro grown under upland conditions

There is a scarcity of basic information on dry matter accumulation by various plant organs, nutrient uptake, and yield of taro [Colocasia esculenta (L.) Schott] grown under upland conditions. These data are essential for the development of technological packages, growth simulation models, and decision support systems designed to promote agrotechnology transfer of the crop in the tropics. Two taro cultivars were planted and harvested for biomass about every six weeks during the growing season. At each harvest, plants were separated into various plant parts and their dry matter and nutrient content were determined. There were no significant differences (P<0.05) in total and edible dry matter content between cultivars. However, cultivar ‘Lila’ absorbed significantly smaller amounts of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and zinc (Zn) than cultivar ‘Blanca’, suggesting that it had a higher nutrient‐use efficiency. Fresh corm yields were not significantly different and averaged 20,221 kg/ha for both cultivars.     

Changes in antioxidant content of tomato fruits in response to cultivar and nutrient solution composition

The aim of this study was to investigate the effect of cationic proportions (K/Ca/Mg) in the nutrient solution on fruit quality (quality attributes and antioxidant content) using a high-pigment, 'Lunarossa', tomato cultivar and a standard tomato cultivar ('Corfù') grown in soilless culture. Treatments were defined by a factorial combination of three nutrient solutions having different cationic proportions and two indeterminately growing round tomato cultivars. A high proportion of K in the nutrient solution increased the quality attributes (fruit dry matter, total soluble solids content) and the lycopene content of tomato fruit, whereas a high proportion of Ca improved tomato fruit yield and reduced the incidence of blossom-end rot (BER). The highest total antioxidant activity was observed in the treatment with a high proportion of Mg in the Lunarossa cultivar. The high-pigment hybrid has provided a higher antioxidant content (lycopene and alpha-tocopherol content) than the commercial hybrid, but it was more susceptible to BER and consequently less productive.     

Effect of Baking Method and Fermentation on Folate Content of Rye and Wheat Breads

The effect of baking method on folates of rye and wheat breads, as well as the effect of sourdough fermentation of rye, were examined. Sourdough fermentations were performed both with and without added yeast, and samples were taken throughout the baking process. Samples were analyzed microbiologically for their total folate content after trienzyme extraction. Individual folate vitamers were determined by HPLC after affinity chromatographic purification. The lowest folate contents for both rye and wheat breads were found from breads baked without added yeast. Total folate content increased considerably during sourdough fermentation due to increased amounts of 10‐HCO‐H₂folate, 5‐CH₃‐H₄folate, and 5‐HCO‐H₄folate. Baker's yeast contributed markedly to the final folate content of bread by synthesizing folates during fermentation. Proofing did not influence total folate content but changes in vitamer distribution were observed. Folate losses in baking were ≈25%. The variety of sourdoughs and baking processes obviously lead to great variation in folate content of rye breads. The possibilities to enhance natural folate content of rye bread by improving folate retention in technological processes and by screening and combining suitable yeasts and lactic acid bacteria should be further investigated.     

Effects of Cultivar,Growing Location,and Year on Physicochemical and Cooking Characteristics of Dry Beans (Phaseolus vulgaris)

The effects of cultivar, growing location, and year on physicochemical and cooking characteristics of beans (Phaseolus vulgaris ) were investigated, and the relationship between these characteristics was determined. Twenty dry bean cultivars and breeding lines were grown at two different locations for two consecutive years (2013 and 2014) in southern Manitoba, Canada. Results indicated that cultivar, growing location, and year had significant effects on seed weight, water hydration capacity, and cooking time of beans. Significant cultivar, location, and year variations in protein, starch, and phytic acid contents in beans were observed. Most of the traits were also significantly affected by the interactions of cultivar × location, cultivar × year, and location × year. Seed weight was negatively correlated with crude protein and ash contents but positively correlated with starch content. Cooking time was negatively correlated with protein, ash, and phytic acid contents but positively correlated with firmness. Phytic acid content in beans was positively correlated with ash content. Knowledge gained from this study will be useful to bean breeders in selecting parental lines for crossing and cultivar development in efforts to improve the quality of beans.     

氮素形态对强筋和中筋小麦产量和品质的影响

[目的]研究不同氮素形态对强筋和中筋小麦植株生长、籽粒蛋白质含量及产量的影响,为选择适宜氮肥种类、提高氮素利用率提供科学依据.[方法]选用强筋小麦'藁优2018'和中筋小麦'济麦22'在河北邢台进行田间试验.在相同施氮量下,设置5个氮源处理:不施氮肥(CK)、酰胺态氮肥(Urea)、铵态氮肥(NH4+-N)、硝态氮肥(...     

Traditional and New Food Uses of Pulses

The global production of pulses, such as various peas, beans, lupines, and lentils, is about 77 million metric tons. Pulses are diverse in their traditional food uses in Asia, Africa, and America, where they have been used, for example, in soups, spreads, meal components, snacks, and breakfast items. Having high protein content (about 20–40%), pulses have recently gained interest when alternative sustainable protein sources are considered. Pulses have been used for protein enrichment in pasta and bread, and they also are suitable ingredients in gluten‐free foods. Wet and dry fractionation methods as well as bioprocessing such as germination and fermentation provide useful tools for development of new functional pulse ingredients. The use of pulses is bound to increase in the future, and especially in combination with cereal raw materials they may find new applications meeting both sensory and nutritional needs of consumers on all continents.     

Genetic Gains in Agronomic and Selected End‐Use Quality Traits over a Century of Plant Breeding of Canada Western Red Spring Wheat

Canadian Western Red Spring (CWRS) market class is the predominant type of wheat (Triticum aestivum L.) grown in Canada since the turn of the 20th century. Wheat cultivars ranging from cv. Red Fife to cv. Superb were field tested in a series of 24 replicated trials spanning 19 years in central Saskatchewan, Canada. The objective of this study was to measure the rate of cultivar improvement in light of relatively narrow end‐use quality definitions for the CWRS market class. Regression of cultivar trait means on year of cultivar registration was used to assess the rate of change in yield, productivity traits, and end‐use quality parameters. Yield levels were estimated to be increasing at a rate of approximately 15 kg/ha per year in 1970 and 23 kg/ha per year in 1995. Days to spike emergence and plant height decreased over time. Kernel weight, grain protein concentration, SDS sedimentation volume, farinograph absorption, and dough development time increased over time, whereas farinograph mixing tolerance index and yellow pigment concentration decreased. The results show that improvement in key agronomic and end‐use traits has been achieved in CWRS wheat.     

Folate content in commercial white and whole wheat sandwich breads

After the U.S. mandate of folic acid fortification of enriched grain products, a report indicated higher than expected fortification. Limited information is available on folic acid in enriched products. We measured the folate content in 92 sandwich breads (46 white breads and 46 whole wheat breads) in Birmingham, Alabama, during 2001-2003. The mean folate content in white bread declined significantly from 2001 to 2002 or 2003, whereas the decline in folate content in whole wheat bread containing enriched flour was not significant. White bread contained significantly more folate than whole wheat bread containing enriched flour in 2001 and 2003. In 2002 and 2003, >40% of breads made of enriched flour contained <115 microg of folate/100 g and >70% contained <160 microg/100 g. These percentages were markedly higher than those in 2001. Our data suggest that folic acid in breads containing enriched flour declined after 2001 and monitoring of fortification may be necessary.