The sourdough fermentation is the powerful process to exploit the potential of legumes,pseudo-cereals and milling by-products in baking industry

Abstract

In the era of fighting wastes and paying close attention to sustainability and new protein sources, legumes, pseudo-cereals and milling by-products deserve all the efforts for increasing their consumption. Even with obvious peculiarities, a common trait characterizes these heterogeneous matrixes: unquestionable nutritional and functional value combined with some technological, sensory and/or anti-nutritional weaknesses, which unfortunately limit the exploitation and consumption. With the perspective of their use to fortify staple baked goods, we reviewed the main technological, nutritional and functional features of various legumes and pseudo-cereals, and milling by-products. Notwithstanding the potential of other technological solutions, we reported numerous evidences that qualified the sourdough fermentation as the most sustainable and powerful process to exploit the technological, nutritional and functional features of these matrixes and to limit or eliminate weak attributes. Sourdough fermentations tailored for specific matrixes allowed the fortification of staple baked goods with abundant levels of legumes, pseudo-cereals or milling by-products while keeping high consumer acceptance.     

Barcode High Resolution Melting (Bar-HRM) analysis for detection and quantification of PDO “Fava Santorinis” (Lathyrus clymenum) adulterants

Legumes considered as one of the most important crops worldwide. Due to high price as a PDO product, commercial products of “Fava Santorinis” are often subjected to adulterations from other legume products coming from other Lathyrus or Vicia and Pisum species. Using plant DNA barcoding regions (trnL and rpoC) coupled with High Resolution Melting (Bar-HRM) we have developed a method allowing us to detect and authenticate PDO “Fava Santorinis”. Bar-HRM proved to be a very sensitive tool able to genotype Lathyrus and its closed relative species and to detect admixtures, being sensitive enough to as low as 1:100 of non-“Fava Santorinis” in “Fava Santorinis” commercial products. In conclusion, Bar-HRM analysis can be a faster, with higher resolution and cost effectiveness alternative method to authenticate PDO “Fava Santorinis” and to quantitatively detect adulterations in “Fava Santorinis” with other relative commercial “Fava” food products.     

大豆异黄酮抗大鼠T细胞衰老及抗氧化作用研究

为研究大豆异黄酮抗大鼠T细胞衰老和抗氧化作用，选用老龄SD大鼠，观察大豆异黄酮对T细胞CD28表达水平及肝脏氧化应激水平的影响。实验设立青年对照组、老龄对照组和大豆异黄酮0．33、0．99g／kgBW剂量组，其中剂量组按剂量灌胃给予大豆异黄酮，对照组灌胃给予等量纯净水。4周后，分别制备肝细胞匀浆和肝单细胞悬液，用硫代巴比妥酸（TBA）比色法测定肝匀浆中丙二醛（MDA）含量，分光光度法测定超氧化物歧化酶（SOD）活力，用流式细胞仪结合双氢罗丹明123（Rh123）和双氢-乙酰乙酸二氯荧光黄（82DCFDA）染色法分别检测肝细胞线粒体膜电位（MMP）及活性氧（ROS）水平；另取外周血测定T淋巴细胞表面CD8／CD28表达情况。结果显示：青年对照组及大豆异黄酮剂量组的肝组织MDA含量均较老年对照组低，而SOD活力及肝细胞MMP水平均较老年对照组高（P〈0．05）；大豆异黄酮剂量组肝细胞内的ROS水平较老年对照组低（P〈0．01）。老年对照组大鼠外周血CD28^＋和CD28^＋／CD8^＋T细胞比例低于青年对照组，而CD28^-／CD8^＋T细胞比例高于青年对照组，给予大豆异黄酮样品组三者比例均介于两对照组之间。提示衰老大鼠外周血T细胞CD28表达降低，肝细胞线粒体膜稳定性下降，氧自由基清除能力下降，过氧化脂质分解的终产物增多；大豆异黄酮可提高老龄大鼠T细胞CD28表达水平，增加肝细胞抗氧化酶活性，稳定线粒体膜电位，减少活性氧产生。     

Antioxidant properties of some commonly consumed and underutilized tropical legumes

The antioxidant properties of some commonly consumed [cowpea (Vigna unguiculata)] and underutilized [pigeon pea (Cajanus cajan) and African yam bean (Sphenostylis sternocarpa)] legumes were assessed with regard to their Vitamin C, total phenol, and phytate content, as well as antioxidant activity as typified by their reducing power and free radical scavenging ability. The Vitamin C content of the cowpeas ranged from 0.5 to 0.9 mg/100 g, while that of underutilized legumes were 0.9 mg/100 g for pigeon pea and 0.8 mg/100 g for African yam beans. The phenol content of the cowpeas were 0.3–1.0 mg/g, African yam bean had 0.7 mg/g total phenols, while pigeon pea contained 0.4 (white) and 1.2 mg/g (brown) total phenol content, respectively. The phytate content of all the legumes [cowpea (2.0–2.9%), pigeon pea (2.0–2.4%), African yam beans (2.4%)] analyzed were generally high, while the reducing power and free radical scavenging ability for all the legumes were very low except in African yam beans (23.6%), cowpea brown (29.9%), and pigeon pea brown (54.5%) that had a relatively high free radical scavenging ability. Therefore, one of the commonly consumed cowpea V. unguiculata (brown) and underutilized legumes C. cajan (brown) and S. sternocarpa could be considered as a functional food due to their relatively higher antioxidant activity (free radical scavenging ability and redox potential) which could be as a result of their relative higher total phenol content.     

Antioxidant activity of protein extracts from heat-treated or thermally processed chickpeas and white beans

In this study, antioxidant activities of water-soluble protein extracts from chickpeas and white beans were investigated. The area under the curve (AUC) values of lyophilized crude protein extracts (dialyzed or undialyzed) from thermally processed (121 °C for 20 min) or heat-treated (90 °C for 20 min) chickpeas (73–91 μmol trolox/g) and white beans (39–67 μmol trolox/g) indicated a higher free radical-scavenging capacity and thermostability for chickpea proteins than for white bean proteins. The thermal processing also increased the Fe⁺²-chelating capacity of lyophilized chickpea crude protein extracts 1.8-fold whereas it caused a 2.3-fold reduction in the Fe⁺²-chelating capacity of lyophilized white bean crude protein extracts. Dialysis increased the protein content of lyophilized chickpea extracts 1.5–2-fold but it did not affect the protein content of lyophilized white bean extracts significantly. Ammonium sulfate precipitation was not effective for selective precipitation of antioxidant proteins. However, it improved the free radical-scavenging capacity of lyophilized protein extracts from thermally processed chickpeas and white beans by almost 25% and 100%, respectively. DEAE-cellulose chromatography, indicated the presence of five (A₁–A₅) and three (B₁–B₃) antioxidant protein fractions in heat-treated and thermally processed chickpea protein extracts, respectively, and can be used for the partial purification of antioxidant proteins. The results of this study showed the good potential of chickpea proteins as thermostable natural food antioxidants.     

高效液相色谱法测定大豆胚轴中DDMP皂甙αg和βg

为检测大豆中的αg和βg含量 ,应用高效液相色谱 -差示折射法 (HPLC -dRI)测定大豆皂甙样品中DDMP皂甙αg和 βg含量 ,色谱柱为ODS -AM - 30 3柱 (YMC ,4 6mm× 2 5 0mm ,5 μm) ,流动相为含 0 1%三氟乙酸的乙腈 水 (4 0 6 0 )。DDMP皂甙αg和 βg分别在 1 38～ 6 88μg和 1 6 2～ 8 12 μg范围内线性关系良好 ,平均回收率为 93 4 %和 94 2 % ,RSD为 4 0 7%和 4 2 8%。方法准确度高 ,重现性好 ,适用于大豆皂甙样品中DDMP皂甙以及其它大豆皂甙的含量测定。     

The effect of delaying autumn incorporation of green manure crop on N mineralization and spring wheat (Triticum aestivum L.) performance

The use of legumes as green manuring crops does involve a potential riskof N leaching losses over the winter period. The susceptibility of cropresidue-derived N to losses and the pre-crop value of a green manuring crop canbe manipulated by proper timing of incorporation into soil. In this study,mineralization of C and N was investigated in a range of low temperatures,including thawing and freezing, that are characteristic to autumn green manureincorporation and its decomposition. The pre-crop effect of green manuring wasfurther tested with spring wheat under field conditions. We hypothesized thatdelaying green manure incorporation in the autumn would reduce the risk of Nlosses from the field and maximize the N transfer to a successive spring wheatcrop. To test the hypothesis, N mineralization was followed in alaboratory experiment where red clover (Trifoliumpratense L.) shoots were incubated at 4–8 °Cfor 40–80 days to simulate early autumn, delayed autumn and late autumnincorporation of a green manuring crop, followed by an incubation at–2 °C or at –2 °C to+4 °C for 25 days to simulate winter conditions. In asimultaneous field experiment, we measured the effect ofdelayed autumn incorporation of common vetch (Vicia sativaL.) green fallow on spring wheat performance. In the laboratoryexperiment, significant N mineralization during incubation wasdetected when simulating both early autumn and delayed autumn incorporation. Incontrast, no net N mineralization was detected when simulating lateincorporation. In the field experiment, the N supply fromsoil to spring wheat was higher in the late and delayed incorporationtreatmentsthan in early or spring incorporation of green manure. Late incorporationalso produced most wheat grain. We conclude that different amounts of N becomeavailable to wheat, depending on the time of incorporation of green manureresidues in soil. This difference is due to temperature. Late or delayedincorporation of green manure residues has the potential to reduce thesusceptibility of mineral N to leaching and yields more N available to asubsequent crop.     

Bioactivity of endosperm extracts from susceptible and resistant bean seeds against Callosobruchus maculatus

Due to their high nutritional value, seeds are often the target of herbivory. In response, plants have evolved a host of adaptations that physically and/or chemically reduce the likelihood of granivory. In grain legumes, the main chemical defences within the endosperm derive from anti-nutritional proteins such as lectins and protease inhibitors. However, less is known about the bioactivity of secondary metabolites found within seeds. Here, solvent extraction was used to identify the major classes of phytochemicals found within the endosperm of both resistant beans (Phaseolus vulgaris) and susceptible beans (Vigna unguiculata). Phenols and terpenoids were recovered from the resistant P. vulgaris seeds only, whilst glycosides and flavonoids were recovered in greater amounts from P. vulgaris in comparison to V. unguiculata. To assess the bioactivity of the extracts against the seed beetle, Callosobruchus maculatus, the extracts were incorporated into artificial seeds and key life-history traits of the beetle determined. The results show the endosperm of both resistant and susceptible beans to contain an ensemble of secondary metabolites that deter oviposition (antixenosis) by adult beetles and disrupt the survival and development of the larvae (antibiosis). However, no extract resulted in complete resistance, indicating that the phytochemicals function alongside other anti-herbivory mechanisms such as α-amylase inhibitors and protease inhibitors. Breeding programmes could potentially select for key phytochemical groups such as terpenoids or glycosides in cultivars in order to optimise the trade-off between resistance and agronomic quality by harnessing the anti-herbivory properties of secondary metabolites in conjunction with anti-nutritional proteins.     

Processing methods for reducing alpha-galactosides in pulses

Abstract

Pulses are an excellent source of protein and dietary fiber and are consumed around the world. Their consumption has been recommended as part of a healthy diet. However, they contain various antinutrients such as tannins and trypsin inhibitors, as well as indigestible carbohydrates called alpha-galactosides. These oligosaccharides are fermented by the microorganisms in the gut, producing gas and causing flatulence in healthy individuals. While this flatulence is undesirable (and results in their low acceptance in the Western diet), alpha-galactosides have also been hypothesized to increase susceptibility to bowel diseases, and their presence in the gut worsens the symptoms of patients with irritable bowel syndrome. The elimination of alpha-galactosides by breeding is difficult as they play a vital role in maintaining seed viability through periods of drought and cold. There is a critical need to evaluate the various post-harvest processing methods, and their effect on alpha-galactoside removal to facilitate commercialization. This paper reviews the effectiveness of methods and processing conditions in alpha-galactoside removal from a variety of pulses.