Seed coat has no value in protecting cowpea seed against attack by Callosobruchus maculatus (F.)

Experiments were conducted to compare the oviposition preference of the cowpea seed beetle Callosobruchus maculatus (F.) on 22 cowpea varieties, with and without seed coat. The cowpeas included five resistant, four moderately resistant and 13 susceptible varieties. Ten of the varieties had smooth seed coats while 12 were wrinkled. Mean numbers of eggs laid on smooth and wrinkled varieties were not significantly different. The survival of the bruchid was also assessed on intact and decorticated seeds of five varieties, comprising two resistant varieties “Kanannado” and “IT89KD-288”, a moderately resistant variety “IT93K-513-2” and two susceptible varieties “IT87K-941-1” and “IT89KD-374-57”. There was no correlation of resistance level with the number of eggs oviposited on cowpea varieties. Under limited and free-choice conditions, cowpea seeds with intact seed coats were preferred to decorticated seeds for oviposition. Adult emergence, mean development periods and pre-adult mortality were similar when seed coats were removed or left intact. It is concluded that the seed coat may not be a useful aspect to consider for breeding of bruchid resistance into cowpea varieties.     

Characterization of new sources of mungbean (Vigna radiata (L.) Wilczek) resistance to bruchids, Callosobruchus spp. (Coleoptera: Bruchidae)

The bruchid beetles Callosobruchus chinensis (L.) and C. maculatus (F.) are destructive pests of stored mungbean (Vigna radiata (L.) Wilczek). The development of resistant mungbean varieties to manage bruchids is a major breeding objective. In the present study, we investigated the characteristics of resistance to C. chinensis and C. maculatus in two new resistant mungbean accessions V1128 and V2817, and two previously reported resistant accessions V2709 and V2802, compared to the susceptible mungbean cultivar, KPS1. Evaluation for resistance to both bruchid species using whole and decorticated seeds revealed that V1128 and V2817 were free from damage, V2709 and V2802 showed partial damage with low or moderate number of bruchids emerging from seeds, and KPS1 showed complete damage with the highest number of bruchids emerged. Comparison of the seeds harvested at seed filling, early maturity and full maturity stages revealed that the percentage of damaged seeds from resistant accessions was lower at all stages compared with KPS1. V1128 and V2817 showed complete resistance against both bruchids regardless of when their seeds were harvested, while resistance in V2709 and V2802 were most pronounced at full maturity, and KPS1 was totally damaged at all times tested. These results suggest that the chemical factor(s) conferring resistance is synthesized as early as the seed filling stage. Evaluation of resistance using artificial seeds showed that increasing the percentage of resistant seed powder adversely affected bruchid growth and development. The number of adults emerging from seeds and number of damaged seeds decreased while adult developmental period increased as the proportion of resistant seed powder increased. The weight of emerging male and female adults of C. maculatus was lighter than those from the seeds containing susceptible seed powder alone. However, C. chinensis adults were not affected by the same test. The results suggest that biochemical(s) in cotyledon tissue are responsible for the resistance and the seed coat had no protective role against the bruchids. Although all four resistant accessions evaluated are useful for mungbean breeding, V1128 and V2817 show complete resistance to both C. chinensis and C. maculatus. Thus, these two new resistant sources may be the most effective for breeding purposes.     

The nutritional and antinutritional attributes of sword bean [Canavalia gladiata (Jacq.) DC.]: an under-utilized tribal pulse from south India

Six accessions [three with maroon‐coloured seed coat and three with white‐coloured seed coat) of sword bean (Canavalia gladiata (Jacq.) DC.], were collected from six different locations in south India. They were analysed for their proximate and mineral composition, amino acid profiles of total seed proteins, in vitro protein digestibility (IVPD) and certain antinutritional factors. The essential amino acid profile of total seed proteins compared favourably with FAO/WHO requirements, except that there were deficiencies of sulphur containing amino acids in all the six accessions and also the leucine, lysine and tryptophan contents were low in maroon‐coloured seed coat accessions. The IVPD of the accessions ranged from 63.39 to 76.92%. Antinutritional substances like total free phenolics, tannins, l ‐DOPA (3,4‐dihydroxyphenylalanine), trypsin inhibitor activity and phytohaemagglutinating activity were also investigated. The antinutritional factors that were detected were thought to have little nutritional significance if the beans are properly processed.     

Composition and bioactive factor content of cowpea (Vigna unguiculata L. Walp) raw meal and protein concentrate

Analysis was done of the composition and bioactive factor content of whole meal, processed meal and protein concentrate from a cowpea cultivar (Vigna unguiculata L. Walp var. IT86D‐719) grown in Yucatan, Mexico and of changes in these parameters after soaking and dehulling. Both meals had a high protein content (247.53 and 257 g kg^?1 dry matter (DM) respectively). The protein concentrate was rich in protein (786 g kg^?1 DM) and lipids (58.47 g kg^?1 DM) and had an amino acid profile similar to that of the processed meal. The amino acid profiles of the meals almost covered human dietary requirements based on FAO/WHO/UNU‐suggested profiles but were deficient in sulphur amino acids. Trypsin inhibitor activity was high in both meals compared with levels found in previous studies. Trypsin inhibitor activity in the concentrate was not eliminated but was significantly reduced. Lectin activity, tannin levels, phytate levels and α‐amylase inhibitor activity were relatively low in the meals, and cyanogenic glucosides were not detected. Residual amounts of α‐amylase inhibitors, tannins and phytate were observed in the concentrate, and lectin activity was not detected. Results indicate that V. unguiculata L. Walp var. IT86D‐719 meals and protein concentrate are good potential foodstuffs in the Yucatan region. Copyright © 2006 Society of Chemical Industry     

Gamma irradiation of cowpea (Vigna unguiculata L. Walp) seeds: effect on colour,cooking quality and pasting characteristics

Cowpea seeds were treated to various gamma irradiation doses, and their colour, cooking quality and pasting properties studied. Irradiation at 50 kGy resulted in significant browning (indicated by decreases in L colour value) of cowpea seeds. At 2 and 10 (but not at 50) kGy, irradiation led to significant reduction in cooking time of cowpea seeds possibly through irradiation‐induced degradation of starch and pectic substances (indicated by decreases in peak and final viscosities) leading possibly to enhanced heat and mass transfer within the seed cotyledon and cell wall, respectively. At 50 kGy, the cooking time of cowpea seeds was prolonged significantly owing possibly to extensive polymer cross‐linking occurring within the seeds at this high dose. Splitting of cowpea cotyledons during cooking decreased significantly at 50 kGy, but was unaffected at 2 and 10 kGy. Irradiation resulted in significant leaching of nutrients from cowpea seeds during cooking in a dose‐dependent manner.     

Resistance of Vigna unguiculata (cowpea) seeds to Callosobruchus maculatus is restricted to cotyledonary tissues

We have investigated the survival of Callosobruchus maculatus larvae when reared on resistant IT81D 1045 Vigna unguiculata seeds, whose resistance has been associated with variant forms of vicilins. Here, we present data which show that larvae of C. maculatus feeding on embryonic axis of resistant cowpea reach a mass of around 28 times higher than those feeding on cotyledonary tissues. Additionally, incorporation of 5–10% of embryonic axis flour on artificial seeds made of resistant flour restores toxicity of seeds to the bruchid. Vicilins purified from both susceptible and resistant embryonic axis had no deleterious effects either on insect development or on insect survival until a level of 4% of incorporation. In contrast, vicilins from resistant cotyledons show an LD₅₀ (50% lethal dose) and WD₅₀ (half weight dose) of 2%. Total vicilin contents of embryonic axes were around two times lower than in cotyledonary tissues, while proteolytic activities of all four proteinase classes were always higher in the former tissues. By 2D‐PAGE we visualized eight protein spots, which seem to be exclusively found on resistant cotyledons. Copyright © 2006 Society of Chemical Industry     

Hard‐to‐cook phenomenon in legumes

Abstract

Hard‐to‐cook legumes (HTCL) have been observed for centuries. Different types of HTCL are recognized in freshly harvested crops or are developed during storage. Two types of hard shell, which is due to seed coat impermeability to water, are identified: (1) the reversible hard shell that occurs in freshly harvested seeds and disappear during storage; (2) the other type is the irreversible hard shell that develops during storage. Sclerema is due to unhydratable cotyledons (despite removal of seed coat) during soaking, and it may develop during storage. Some cases of reported hard shell may be due to sclerema, since no testing was done to prove seed coat impermeability. Hard texture and sandy texture (i.e., grainy or granular texture) have been noticed in freshly harvested and in stored legumes. In this paper, variations in the physical properties and the chemical composition of the seeds of different legumes and of different varieties are summarized in several tables. The following topics are discussed with regard to different types of HTCL: the environmental factors affecting their development; the structural and the chemical changes associated with their presence; the treatments which are used or suggested to control their development or to improve the texture of HTCL; and the possible relations between these subjects. Several propositions concerning the mechanisms involved in hard‐texture seeds are discussed. Soft texture is associated with ease of cell separation of the cotyledons in cooked legumes, indicating the significance of the middle lamella and the cell wall. At present, it seems that the main mechanisms include phytate, phenolic compounds, and divalent cations (Ca, Mg) and their interaction with pectic substances and proteins. Starch, lipids, tannins, and lignin may have a secondary effect. More knowledge is needed about cell wall components, structure, and interactions, and about the effect of environmental conditions on them.     

Electroantennogram and behavioral responses of Pteromalus cerealellae to odor stimuli associated with its host, Callosobruchus maculatus

Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae) is a generalist parasitoid of the larvae of many stored-product insects, including the cowpea seed beetle, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae), which live endophytically in cowpea seeds. The role of host-related semiochemicals in the host location behavior of this parasitoid was investigated using electroantennogram (EAG) and behavioral (olfactometer) techniques. Responses of mated and unmated female P. cerealellae were tested to a variety of host-related chemical stimuli including hexane extracts of uninfested cowpea seeds, (bruchid)-infested cowpea seeds, bruchid larvae (whole body or WB), larval frass, adult female bruchids (WB), and adult male bruchids (WB). All of the tested stimuli elicited significant EAG responses in unmated and mated female P. cerealellae, with mated females exhibiting a greater EAG response than unmated females to some treatments. Results from Y-tube olfactometer bioassays demonstrated a significant response of mated female P. cerealellae to extracts of uninfested cowpea seeds, infested cowpea seeds, adult female bruchids, bruchid larvae, and larval frass, but no significant response was elicited by the extract of adult male bruchids. Pair-wise comparisons of the four most attractive stimuli (i.e. uninfested seeds, infested seeds, bruchid larvae, and larval frass) in a four-way olfactometer showed preference of mated female P. cerealellae for the extract of uninfested cowpea seeds compared to larval frass extract. No significant differences were recorded between other paired treatments. These results suggest the relative importance of volatile cues from seeds (host habitat) in mediating host location by P. cerealellae.     

Biochemical characterisation of α-amylase inhibitors from Achyranthes aspera and their interactions with digestive amylases of coleopteran and lepidopteran insects

BACKGROUND: Starchy seeds are an important food and a source of dietary ingredients in many countries. However, they suffer from extensive predation by bruchids (weevils) and other pests. α‐Amylase inhibitors are attractive candidates for the control of seed weevils, as these insects are highly dependent on starch as an energy source. RESULTS: A proteinaceous α‐amylase inhibitor from the seeds of Achyranthes aspera was identified, purified and characterised. In electrophoretic analysis, two prominent amylase inhibitor activity bands (AI1 and AI2) were detected. The inhibitor was purified 9.99‐fold with 1206.95 total amylase inhibitor units mg^?1 protein. The molecular weight of the purified inhibitor was around 6 kDa. The isolated α‐amylase inhibitor was found to be resistant to heat and proteolysis. Feeding analysis of Callosobruchus maculatus larvae on a diet containing seed powder of A. aspera revealed that survival of the larvae was severely affected, with the highest mortality rate occurring on the fifth day of feeding. The isolated inhibitor inhibited the majority of amylase isoforms of C. maculatus, Tribolium confusum and Helicoverpa armigera in electrophoretic analysis and solution assays. CONCLUSION: The information obtained in the present investigation could be useful for a genetic engineering approach that would make seeds resistant to storage pest infestations. Copyright © 2011 Society of Chemical Industry     

Screening grape seeds recovered from winemaking by‐products as sources of reducing agents and mammalian α‐glucosidase and α‐amylase inhibitors

Grape seeds collected from vinification of various grape varieties were extracted by supercritical CO₂ for oil recovery. The defatted residues thus obtained were considered as a re‐utilisable co‐product and assessed for phenolic content, reducing capacity and inhibitory activities against mammalian α‐amylase and α‐glucosidase enzymes. Supercritical CO₂ treatment led to higher recovery of anthocyanins. Reducing capacity of phenolic extracts reached up to ~2200 mmolFe(II) kg^?1, much higher than that of various natural phenolic sources. The anthocyanin‐rich extracts showed the highest inhibitory effectiveness towards α‐glucosidase (I₅₀ value equal to ~40 μg gallic acid equivalents (GAE)/mL ~ half than acarbose). Inhibitory effectiveness towards α‐amylase activity was similar among grape varieties, with I₅₀ values comparable to that of acarbose and correlated with proanthocyanidin contents. These results could pave the way for an efficient processing of grapes, including cascade processes, namely: winemaking, oil extraction from recovered grape seeds and phenolic extraction from defatted grape seeds as potential cost‐effective nutraceuticals.     

Primary and secondary metabolite compounds in cowpea seeds resistant to the cowpea bruchid [Callosobruchus maculatus (F.)] in postharvest storage

Cowpea is a one important legume crop in Sub-Saharan Africa due to its high content of protein and other nutrients. However, seeds of cowpea varieties are destroyed by Callosobruchus maculatus in storage. This study investigated various biochemical compounds of susceptible and resistant cowpea genotypes, to determine the biochemical compounds underlying cowpea resistance to bruchid. Six cowpea genotypes were analyzed in three replicates. One-way analysis of variance, Pearson correlation and path analysis were used to determine the influence of the biochemical compounds on the cowpea status. Amongst the cowpea genotypes assayed the biochemical compounds analyzed (Vicilin; α-amylase Inhibitor; Phenols; Condensed Tannin; Tannin; Carbohydrate; Flavonoid and Protein), were present in amounts. Resistant genotypes exhibited higher contents of Phenols (22.29 mg/g for WC66*5T and 19.74 mg/g for WC36); Tannin (2.45CEmg/g for WC36 and 2.52CEmg/g for TVU13677); and Carbohydrate (72.82% for TVU13677 and 71.09% for WC36). The most susceptible genotypes had the lowest content of Phenols (13.5 mg/g for TVU946 and 12.72 mg/g for Glessissaffodo); Tannin (0.74CEmg/g for Akounado and 0.97CEmg/g for Glessissaffodo) and Carbohydrate (60.95% for Akounado and 61.39% for TVU946), while Condensed Tannin was associated to their seed coat colour but not to their resistance status against bruchid. The resistant genotypes TVU13677; WC36 and WC66*5T were found to contain a higher amount of a subset of biochemical compounds as defensive compounds against cowpea bruchid. The susceptible cowpea genotypes (Akounado; Glessissaffodo; TVU946) screened for their biochemical content presented low amounts of these defensive compounds. The path analysis implemented highlighted the existence of causal relationships among biochemical compounds analyzed and resistance parameters, thus revealing the resistance basis of cowpea seed biochemical compounds. These latter results point out the possibilities to consider the presence of these biochemical compounds underlying the resistance of cowpea to bruchid in the breeding program toward the resistance to bruchid.     

Influence of cowpea (Vigna unguiculata L Walp) variety on protein quality and sensory properties of akara,a popular West African cowpea‐based food

The influence of newly developed cowpea varieties (IT81D‐699, IT82E‐18, IT84S‐2246‐4 and TV_x3236) on the proximate composition, protein quality and sensory properties of akara, a popular West African cowpea‐based food, was investigated and the results obtained were compared with those for akara prepared from a local blackeye cowpea variety. Protein quality was evaluated using weanling albino rats fed diets which were formulated to supply 10% protein using defatted akara samples, with casein as a control. Akara samples prepared from IT81D‐699 and TV_x3236 had crude protein contents, texture and overall acceptability comparable to those of akara prepared from the blackeye variety. Also, akara diets formulated using IT81D‐699 and TV_x3236 showed significantly (p < 0.05) higher values for weight gain, protein efficiency ratio, net protein ratio and true digestibility than diets formulated with IT82E‐18, IT84S‐2246‐4 and blackeye, suggesting an improvement in the nutritional quality of akara produced using these (IT8ID‐699 and TV_x3236) newly developed cowpea varieties. Copyright © 2004 Society of Chemical Industry     

Cowpea cooking characteristics as affected by micronisation temperature: a study of the physicochemical and functional properties of starch

Bechuana white cowpeas were micronised to three temperatures (130, 153 and 170 °C). Cooking properties of the cowpea seeds and the role of starch‐related properties were studied. In all cases, micronisation significantly reduced the cooking time and thus the time required for the cowpea seeds to attain a suitably soft texture. This was attributed in part to the significant improvement in rate of water absorption during cooking and starch pre‐gelatinisation, as evidenced by loss of birefringence and increased susceptibility of the cowpea starch to α‐amylase digestion. However, micronisation to 170 °C resulted in a severe deterioration in pasting properties of the cowpea flour, possibly due to starch depolymerisation and/or amylose‐associated crosslinking. Owing to these changes, cowpea seeds micronised to 170 °C required a longer cooking time than the other two micronised samples. Flour prepared from cowpea seeds micronised to 170 °C may have limited starch functionality. Copyright © 2006 Society of Chemical Industry     

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α‐glucosidase and α‐amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA‐05 and its wild‐type variety Hwachia against aldose reductase, α‐glucosidase and α‐amylase were examined. The results indicated that the polyphenolics‐rich extracts obtained using 800 g kg^?1 methanol and 500 g kg^?1 ethanol demonstrated inhibitory activities against aldose reductase (IC₅₀ of 0.36–0.46 mg mL^?1) and α‐glucosidase (IC₅₀ of 1.32–1.94 mg mL^?1). The 500 g kg^?1 ethanol extracts also showed α‐amylase inhibitory activities (IC₅₀ of 70.11–80.22 μg mL^?1). Subsequent extracts, prepared further with NaCl and H₂O from precipitates of 800 g kg^?1 methanol or 500 g kg^?1 ethanol extracts, exhibited potent α‐amylase inhibitory activities (IC₅₀ of 17.68–38.68 μg mL^?1). A combination of 500 g kg^?1 ethanol extraction plus a subsequent H₂O extraction produced highest polyphenolics and α‐amylase inhibitors. The SA‐05 α‐amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA‐05 is an advantageous choice for producing anti‐hyperglycaemic compounds.     

Inhibitory potential of phenylpropanoid glycosides from Ligustrum purpurascens Kudingcha against α‐glucosidase and α‐amylase in vitro

The leaves of Ligustrum purpurascens are used in a Chinese traditional tea called small‐leaved kudingcha, which is rich in phenylpropanoid glycosides (PPGs) and has many beneficial properties. Two critical exoacting glycoside hydrolase enzymes (glucosidases) involved in carbohydrate digestion are α‐glucosidase and α‐amylase. We investigated the properties of PPGs from L. purpurascens for inhibiting α‐amylase and α‐glucosidase activity in vitro and found IC₅₀ values of 1.02 and 0.73 mg mL^?1, respectively. The patterns of inhibiting both α‐amylase and α‐glucosidase were mixed‐inhibition type. Multispectroscopy and molecular docking studies indicated that the interaction between PPGs and α‐amylase and α‐glucosidase altered the conformation of enzymes, with binding at the site close to the active site of enzymes resulting in changed enzyme activity. Our studies may help in the further health use of small‐leaved kudingcha.     

Nutritive value and antinutritional factors in different varieties of Sesbania seeds and their morphological fractions

Four different Sesbania seeds, S. aculeata, S. rostrata, S. sesban (accession 10865D) and S. sesban (accession 15019D), were analysed for their physicochemical properties, nutritive values and antinutritional factors (ANFs) in order to assess feasibility of use as an unconventional food resource. Seeds of both the accessions of S. sesban were smaller in size but their seed coat+endosperm fractions were higher (56–57%) than those of S. aculeata and S. rostrata (49–51%). S. rostrata had a lower hydration capacity, hydration index, swelling capacity and swelling index than other seeds. The crude protein content in different seeds ranged from 29.1 to 33.1%, crude lipid 4.7–6.0%, crude fibre 10.9–15.8%, total crude carbohydrates 44.6–47.4% and gross energy 19.2–20.0 kJ/g. Except for isoleucine, histidine and tryptophan, all other essential amino acids were deficient compared to the FAO/WHO reference pattern. The seed fractions showed similar amino acid pattern to that of whole seed with slightly higher values. Palmitic, stearic, oleic, linoleic and linolenic acids were the major fatty acids (FAs) and the total unsaturated and essential FAs ranged from 78.1 to 82.3% and 77.2 to 80.3%, respectively, with S. aculeata having the highest value. The ranges of starch fractions in different seeds were: total starch 17.5–20.4%, digestible starch 7.3–10.2% and resistant starch 10.2–11.2%. The soluble sugar contents ranged from 8.8 to 10.6%. The ranges of antinutritional factors in different seeds were: total phenols 2.96–5.95%, tannins 1.97–2.25%, condensed tannins 1.82–5.14%, phytic acid 1.89–2.37%, saponins 0.52–1.46%, trypsin inhibitors 5.25–14.0 (mg trypsin inhibited per gram of sample) and lectin activity 10.2–20.5 units. There was a wide variation in the ANFs contents of seed coat+endosperm, and cotyledons.     

Legume seed vicilins (7S storage proteins) interfere with the development of the cowpea weevil (Callosobruchus maculatus (F))

Vicilins (7S storage proteins) isolated from the seeds of the legumes Vigna unguiculata (cowpea), Vigna angularis (adzuki bean), Canavalia ensiformis (jack bean), Glycine max (soybean), Phaseolus vulgaris (common bean) and Phaseolus lunatus (lima bean) were shown to be immunologically related and to bind to a chitin matrix. The effect of the isolated vicilins on the development of the cowpea weevil Callosobruchus maculatus was examined. Vicilins from all non-host seeds, including those of the C maculatus-resistant cowpea line IT81D-1045, strongly inhibited larval development (ED₅₀ of 1·07±0·32% to 2·22±0·64%). Vicilins from the C maculatus-susceptible cowpea CE-31 and adzuki bean seeds were the exception with ED₅₀ of 6·25±0·75% and 5·40±1·54%, respectively. These results correlate well with the host range of C maculatus and are possibly a reflection of the low digestibility of vicilins by insect midgut proteinases in addition to the ability they show in binding to chitin-containing structures like the ones found in the bruchid midguts. © 1998 SCI.     

Interaction of aqueous extracts of two varieties of Yam tubers (Dioscorea spp) on some key enzymes linked to type 2 Diabetes in vitro

This study sought to assess the effect of processing of yam flour [from white yam (Dioscorea rotundata) and water yam (Dioscorea alata)] to paste, on the antioxidant properties and inhibition of key enzymes linked to type‐2 diabetes (α‐amylase and α‐glucosidase). The phenolic content (phenol and flavonoid), antioxidant properties, α‐amylase and α‐glucosidase inhibitory properties of the aqueous extracts of the yam products were determined. Processing into paste caused significant (P < 0.05) percentage decrease in their total phenol and flavonoid content of the yam varieties. However, significant increase (P < 0.05) in the antioxidant properties of the yam varieties was observed after processing. Furthermore, the yam extracts inhibited α‐amylase and α‐glucosidase activities in vitro in a dose‐dependent parttern (1–4 mg mL^?1), however, the pasting process caused significant (P < 0.05) decrease in the α‐amylase inhibitory and α‐glucosidase inhibitory activities. Therefore, processing the yam varieties into paste (browned) could potentially increase their antioxidant capacity as well as decreasing their α‐amylase and α‐glucosidase inhibitory properties.     

Impregnated bags for safer storage of legume grains in West and Central Africa

The use of jute bags impregnated with aqueous extracts from two insecticidal plants, Chenopodium ambrosioides and Lantana camara, to reduce damage to stored legume seeds by two major bruchid insect pests, Acanthoscelides obtectus and Callosobruchus maculatus, was compared with a direct seed-treatment method using plant powders. In the first method bags were treated with a 10% concentration of the aqueous plant extract and filled with bean or cowpea seeds, whereas in the second method seeds were thoroughly mixed with leaf powder from the same plants at the rate of 4% (w/w). The bag-treatment method significantly reduced seed damage compared with the untreated control after 6 months of storage (4- to 6-fold decrease in percentage seed damage). Even though relatively low (? 20%), damage by the two insect species controlled by this method was significantly higher than the damage recorded in the seed-treatment method. Orthogonal contrast analysis across test insects showed a significant seed damage difference between treatments with C. ambrosioides and those with L. camara, the latter having the lowest damage profile. The biosafety implication of the use of plant extract-impregnated bags for the protection of food grains against damage by storage bruchid pests is highlighted.     

Distribution of fatty acids in edible organs and seed fractions of borage (Borago officinalis L.)

BACKGROUND: Borage (Borago officinalis L.) is currently used as a vegetable in the north of Spain. The edible parts of the plant are the petioles, leaves and stems. The objective of this study was to determine the oil and fatty acids content in the edible tissues (leaves, petioles and stems) and seed fractions (endosperm + cotyledon, seed coat and elaiosome) of white‐ and blue‐flowered borage accessions. RESULTS: Leaves showed higher mean values of oil content (2.7%) than petioles and stems (1.1% and 1.4%, respectively) in both, blue‐ and white‐flowered material. The most abundant fatty acids in leaves were palmitic, linoleic, α‐linolenic and stearidonic acids (about 75% of the total fatty acids), while in petioles and stems myristic and linoleic acids were most abundant (about 60% of the total fatty acids). Palmitic, oleic, linoleic and γ‐linolenic (GLA) acids were the major fatty acids of seed coat and endosperm + cotyledon in borage seeds (85% of the total fatty acids), while palmitic, stearic, oleic and linoleic acids were the most abundant fatty acids of elaisome in borage seeds (80% of the total fatty acids). CONCLUSION: This paper shows that green parts of borage contain substantial amounts of omega‐3 and omega‐6 fatty acids, which are essential fatty acids for animal and human nutrition. Thus, borage could be a ‘power food’ of the future because of its content of unsaturated fatty acids, particularly the essential fatty acids, which have great potential to prevent cardiovascular disease, cancer and infectious diseases. Copyright © 2007 Society of Chemical Industry