Biological importance of γ-glutamyl-S-methylcysteine of kidney bean (Phaseolus vulgaris L.)

The effects of S-methyl-L-cysteine (SMC) on growth and food intake by rats were investigated and in vivo absorption studies of gamma-glutamyl-S-methyl-L-cysteine and free SMC were performed. The results showed that the peptide is slowly absorbed and only free SMC could be detected in the blood. The diets (10% casein), containing SMC, depressed food intake and animals’ growth. Both effects were proportional to the SMC contents in the diets. The results obtained with pair-fed groups led to the conclusion that the depression in growth was caused by the refusal of the SMC diets. The addition of cystine to the SMC diet only partially restored normal growth. Histological examination of livers, kidneys and spleens of rats fed with SMC showed no tissue alterations, except for a significant increase in the kidney weights. The hematological features did not show any significant differences, but there was a slight increase in erythroid precursors and young forms in the bone marrow, which might indicate an increased erythrocyte turnover. These results suggest that the reduction in food intake could be associated with some defence mechanism against toxic substances.     

Effect of γ-irradiation on the antioxidant activity of turmeric (Curcuma longa L.) extracts

Effect of γ-irradiation (10KGy) on the antioxidant property of turmeric extracts was investigated. γ-irradiated as well as non-irradiated turmeric samples were subjected to successive solvent extraction using hexane, benzene, and 80% aq. methanol. Benzene extract, containing mainly curcuminoids were subjected to column fractionation in order to isolate the individual curcuminoids. The curcuminoid analogues as well as the above fractions were then tested for their antioxidant activity by measuring thiobarbituric acid value (TBAV) and peroxide value (PV) based on the air oxidation of linoleic acid. γ-irradiation at a dose of 10KGy did not affect the antioxidant activity of turmeric extracts studied.     

糖甜菜(Beta vulgaris.L.)体细胞减数分裂形态的初步观察

体细胞减数分裂,在许多动植物中已有报道。紫万年青、葱属、大麦、棉花和玉米等,在根尖组织,或珠心组织,或胚乳发现了减数分裂。幼蚊的回肠、哺乳类动物的肿瘤病变组织也发现减数分裂。因比体细胞减数分裂被认为是自然界普遍存在的一种现象。在低温、核酸钠盐、某些氨基酸以及如秋水仙碱等作用下,体细胞减数分裂频率有增长的趋势。我国学者郑国锠等分别对紫万年青、水稻、玉米等减数分裂做过观察和研究。甜菜物种和糖甜菜品种中,存在着二倍体、三倍体、四倍体不同倍数性的材料,对研究体细胞减数分裂应是适宜的。但这方面的研究,我们尚未见到报道,本文仅就二倍体糖甜菜体细胞减数分裂的一般形态,提出初步观察的报告。     

Effect of γ-irradiation on antioxidant activity of black pepper (Piper nigrum L.)

Antioxidant activity and EPR investigations of irradiated ground black pepper (Piper nigrum L.) were evaluated. The black pepper was exposed to γ-irradiation at doses from 5 to 30 kGy. The effect of irradiation on antioxidant properties of black pepper extracts was investigated by radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, by determination of reducing power and content of thiobarbituric acid-reactive substances. Some significant changes were observed in creation of thiobarbituric acid-reactive substances (TBARS). Difference between non-irradiated and irradiated samples at the legal European limit dose of 10 kGy reached, on average, 23% and, at the Food and Drug Administration (FDA) 30 kGy limit, 33%. Irradiation affected significantly the DPPH radical-scavenging activity and reducing power of ground black pepper extracts. The γ-radiation treatment of ground black pepper samples observed by EPR, resulted in the production of three paramagnetic species (GI–GIII) characterized by different origin, thermal behaviour and stability. The axially symmetric EPR resonances, GI and GII, were assigned to the carbohydrate radical structures. The spin Hamiltonian parameters of GIII possessed the characteristic features of “cellulosic” radical species. The EPR measurements, performed 20 weeks after the radiation process, confirmed that temperature increase from 298 to 353 K, caused significant decrease of integral EPR signal intensity for γ-irradiated samples (∼40%), compared to the reference (non-irradiated) ground black pepper, where only 13% drop was found. Significant correlation between EPR and thiobarbituric acid methods was assessed by study of antioxidant activity changes in relation to irradiation doses and also in the case of spice storage, between EPR and reducing power methods.     

Assessment of crtRB1 Polymorphism Associated with Increased β-Carotene Content in Maize (Zea mays L.) Seeds

Breeding for increasing β-carotene levels in maize (Zea mays L.) kernel aims to address the dietary vitamin A deficiency. Due to 3’TE polymorphism, the crtRB1gene (that encodes β -carotene hydroxylase 1) exists in the three allelic forms, viz., 3’TE allele 1 (termed favorable allele, for it favors higher β-carotene accumulation in kernels), 3’TE allele 2 and 3’TE allele 3 (both termed unfavorable alleles, for they do not favor β-carotene accumulation). Here, we aimed to identify maize lines with favorable allele. First, 3’TE polymorphism assay in 210 inbreds revealed that only “UMI 176” had the favorable allele while the rest had the unfavorable alleles, confirming the previous finding that favorable allele is rare in frequency. Second, β-carotene content analysis in 24 inbreds revealed that it varied from 4.5 to 7.92 (μg/g), 0.23 to 2, and 0.42 to 4.22 for lines with allele 1, 2, and 3 respectively, corroborating the previous findings that the presence of favorable allele correlates with higher β-carotene content. In summary, UMI 176 has the favorable allele and had the highest amount of β-carotene content (7.92 μg/g), indicating that it is a promising donor line that can be utilized in β-carotene biofortification breeding.     

Effect of heat processing on oxazolidine of Capparis masaikai LévI.

Capparis masaikai, as a Chinese local plant, its mature seeds are used in traditional Chinese medicine and commonly chewed for their sweet taste. However, the seeds also contain 2-hydroxyethylglucosinolate (2-Hydr GLS), which can be hydrolyzed by the myrosinase enzyme to product bitterness and harmful substance 1,3-oxazolidine-2-thione (OZT). In this study, heat processing has been used to reduce the OZT in C. masaikai seeds. The effect of heat processing on myrosinase enzymatic activity, 2-Hydr GLS content and water content has been investigated by incubation under different temperatures (30–90°C). Further experiments using mice model showed that feeding of heat processed C. masaikai seeds eliminated the content of OZT in mice blood. Thus, our study indicated that heat processing could be used as an effective method to reduce the harmful OZT and improve the taste of C. masaikai seeds.     

Effect of enzyme treatment with β-glucosidase on antioxidant capacity of mulberry (Morus alba L.) leaf extract

This study was carried out to investigate the effect of enzyme treatment with β-glucosidase on antioxidant capacity of the mulberry leaf extract (MLE) using oxygen radical absorbance capacity (ORAC) and cellular antioxidant capacity (CAC) assay. The MLE was prepared by autoclaving at 121°C for 15 min and treated with β-glucosidase for 9 hr. High pressure liquid chromatography (HPLC) analysis showed that only qercetin-3-β-d-glucose (QT-G) among quercetin (QT) glycosides of MLE, including QT-G, quercetin-3-O-glucose-6″-acetate (QT-GA), and rutin (RT), was converted into QT by 3 hr treatment with β-glucosidase. The in vitro peroxyl radical- and hydroxyl radical scavenging capacity significantly increased after the enzyme treatment using β-glucosidase for 6 and 9 hr, respectively. The metal chelating activity increased after the enzyme treatment using β-glucosidase for 3 hr. The intracellular antioxidant capacity of MLE to protect AAPH- and Cu²⁺-induced oxidative stress in HepG2 cells significantly increased after the enzyme treatment using β-glucosidase for 3 and 6 hr, respectively, indicating that QT may be released from QT-G by β-glucosidase and penetrate into cell membrane so that it can contribute to the intracellular antioxidant capacity of MLE.     

Effect of γ-irradiation on the physicochemical and sensory properties of cashew nuts (Anacardium occidentale L.)

The present study evaluated cashew nuts' quality as a function of γ-irradiation dose in order to determine dose levels causing minimal undesirable changes to the product. Physicochemical (colour, peroxide value, hexanal content, fatty acid composition, volatile compounds) and sensory (colour, texture, odor, taste) properties of cashew nuts were determined after irradiation at doses up to 7 kGy. Results showed a five-fold increase in peroxide value (PV) and a two-fold increase in hexanal content after irradiation at a dose of 7 kGy. Of the fatty acids determined, stearic acid concentration increased while oleic acid decreased with irradiation dose. PUFA were unaffected by irradiation. Volatile compounds such as aldehydes, ketones and alcohols increased after irradiation indicating enhanced lipid oxidation. Colour parameter a∗ increased (p < 0.05) at doses >3 kGy while colour parameters L∗ and b∗ remained unaffected by irradiation. Sensory analysis showed that cashew nuts remained organoleptically acceptable at doses <3 kGy.     

Effect of cassava starch coating on quality and shelf life of fresh-cut pineapple (Ananas comosus L. Merril cv "Pérola")

This research studied the influence of treatment with ascorbic acid, citric acid, and calcium lactate dipping and cassava starch edible coatings on quality parameters and shelf life of fresh-cut pineapple in slices during 12 d at 5 °C. After previous tests, the treatments selected for this study were samples dipped into antibrowning solution with 0.5% of ascorbic acid and 1% of citric acid, with and without 2% of calcium lactate and coated with 2% of cassava starch suspensions. Changes in weight loss, juice leakage, mechanical properties (stress at failure), color parameters (L* and H*), ascorbic acid content, sensory acceptance, and microbial growth of fruits were evaluated. Samples only treated with antibrowning agents were used as control. Edible coatings with and without calcium lactate were efficient in reducing weight loss, juice leakage, and maintaining firmness during storage. However, these samples showed more browning and the ascorbic acid content was reduced. All treatments presented good sensory acceptance (scores above 6). The determining factor of shelf life of pineapple slices was the microbial spoilage. A shelf life of 8 d was obtained for pineapple slices only treated with antibrowning agents. On the other hand, coated samples showed a reduced shelf life of 7 d and higher yeast and mold growth. Thus, although cassava starch coatings were efficient in reducing respiration rate, weight loss, and juice leakage and maintained mechanical properties, these treatments were not able to increase the shelf life of minimally processed pineapple. Practical Application: Pineapple fruit is highly appreciated for its aroma, flavor, and juiciness, but its immediate consumption is difficult. Therefore, pineapple is a potential fruit for minimal processing. However, shelf life of fresh-cut pineapple is very limited by changes in color, texture, appearance, off-flavors, and microbial growth. The use of edible coatings as gas and water vapor barrier and antibrowning agents can extend the storage time and maintain the quality of fresh-cut produce. Cassava starch and alginate coatings are alternative to preserve minimally processed pineapples without changing the quality parameters of fresh fruit. Thus, this study is useful for consumers and fresh-cut industry interested in knowing factors affecting shelf life and quality of fresh-cut pineapple.     

Effect of γ-irradiation on bioactivity, fatty acid compositions and volatile compounds of clary sage seed (Salvia sclarea L.)

Clary sage seeds (Salvia sclarea L.) were obtained from plants cultivated, and 2.5, 4.0, 5.5, and 7.0 kGy doses of γ-irradiation were applied to the clary sage seeds. They were then analyzed for their protein, ash, oil and dry matter contents, and fatty acid composition. Additionally, the total phenolic contents, antiradical, antioxidant activities, and volatile compounds of the clary sage seed extract were determined. There was no significant difference in protein content. However, the moisture, oil, and ash contents of the samples were affected by irradiation. While the 7 kGy dose had a positive effect on the total phenolic content and antiradical activity of the sage seed extract, all doses have negative effects on the antioxidant activity of the sage seed. The main fatty acid of the sage seed was remarkably found as α-linolenic acid. The four irradiation levels caused significant differences in fatty acid composition by affecting all fatty acids except palmitic, palmitoleic, and eicosenoic acids. The dominant volatile compounds of control sage seed were found as β-pinene (18.81%) and limonene (15.60%). Higher doses of the irradiation decreased volatile components of sage seed. Clary sage seed including high omega-3 can be irradiated with low doses (≤ 2.5 kGy) of γ-irradiation. PRACTICAL APPLICATION: Clary sage is one of the most popular Salvia species in Turkey and many countries. Clary sage seed has approximately 29% oil content and this oil contains >50% of α-linolenic acid. γ-Irradiation is widely applied in the preservation of spice quality. The present study shows that the antioxidant activity of the clary sage seed is decreased by γ-irradiation. Additionally, higher doses of irradiation also decreased the volatile components of sage seed. Therefore, we suggest that clary sage seed which includes high levels of omega-3 should be irradiated with low doses (≤ 2.5 kGy) of γ-irradiation.     

Effects of γ-irradiation on the biological activity of burdock (Arctium lappa L.) extracts

Burdock (Arctium lappa L.) extracts were prepared with different extraction methods, ethanol (70%, RT) and hot water (85°C for 3 hr, HT), and their biological activities were investigated after γ-irradiation (10 and 20 kGy). Color of the burdock extracts became brighter after application of irradiation regardless of the extraction system. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the burdock extracts with RT and HT were 54.56 and 59.21% at 500 ppm, respectively, and the lipid oxidation of oil emulsion was delayed by addition of the extracts. The HT29 cancer cell viability was inhibited by burdock extracts with RT up to 52.45 at a 250 ppm level. The anti-mutagenicitiy against 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole and 2-nitrofluorene were also found. Results indicate that burdock extract possesses biological activities and RT showed an increasing trend in antixodiative activity and inhibition of cancer cell viability. Brighter color of the burdock extract after irradiation may improve industrial applicability.     

Use of sodium nitrite in salt-curing of Atlantic salmon (Salmo salar L.) – Impact on product quality

Quality changes during processing and quality differences in smoked fillets of Atlantic salmon (4–5 kg) salted with nitrite salt compared to table salted fillets were measured. Quality parameters from right-side fillets dry salted with nitrite salt were compared with the respective left-side fillets treated the same way with table salt. Ten raw right-side fillets were analysed and used as raw material reference. Use of nitrite salt in salt-curing of smoked salmon affected colour to a more reddish hue, tended to increase carotenoid stability and displayed positive effects on NaCl diffusivity. Only slight weight changes and change in texture properties were revealed. The use of nitrite salt displayed no adverse effects like increased content of N-nitrosoamines in smoked products. In fact, significant lower contents of N-nitrosoamines were found in nitrite salted smoked fillets compared to smoked fillets salted with table salt. Relatively high amounts of residual nitrite in nitrite-treated fillets seem to be the most prominent adverse effect caused by the use of nitrite salt in salt-curing of smoked Atlantic salmon.     

The effectiveness of low temperature (5 °C) on Sitophilus oryzae (L.), Sitophilus zeamais (Motch.) and Sitophilus granarius (L.) in wheat grain: The impact of pre-acclimation

Laboratory trials were conducted in wheat grain to assess the effectiveness of low temperature (5 °C), applied at intervals of 5, 7, 9, 11, 20, 25, 30 and 35 days (d), as a control measure for stored product insect pests of the genus Sitophilus, and compared the results with the impacts of 7 d pre-acclimation at 15 °C and non-acclimation. Mortality was determined after 1, 2 and 7 d of recovery in the laboratory at 25 ± 1 °C and 60 ± 5% r. h., while progeny were assessed 7 weeks later. Acclimation had the strongest impact on S. oryzae after 5 d exposure to 5 °C and 7 d recovery, while the same effect on S. zeamais was shown after 20 and 25 d of exposure and 1 d recovery, and the same impact on S. granarius occurred after 30 and 20 d of exposure and 1 and 7 d recovery, respectively. Low temperature was found to be the most effective against S. oryzae, and the least effective against S. granarius. Mortality was high (≥96%) in both S. oryzae test groups after 11 d of exposure and 7 d recovery, S. zeamais mortality was high (>97%) after 35 and 30 d of exposure and 2 and 7 d of recovery, respectively, and S. granarius mortality was ≤87% in all test variants. Total reduction (100%) of non-acclimated S. oryzae, S. zeamais and S. granarius progeny required 8, 25 and 30 d of exposure to 5 °C, respectively, while acclimated weevils required 11, 30 and 30 d, respectively.     

Moisture-mediated effects of γ-irradiation on antioxidant properties of mung bean (Vigna radiate L.) cultivars

The present investigation is the very first report about the effect of γ-irradiation along with moisture on antioxidant properties of mung bean. Mung bean cultivars were conditioned to moisture level of 10 (control), 12, and 14% and treated with different doses of γ-irradiation (1.0, 2.5, and 5.0 kGy). The total phenolic content (TPC) decreased upon very low (1 kGy) and low dose (2.5 kGy) of γ-irradiation while significantly increased upon further increase in dose (5 kGy) at 10% moisture. However, γ-irradiation (1 and 2.5 kGy) at 12% moisture increased the TPC by 8 and 9%, respectively, and at 5 kGy dose lowered by 15% as compared to control. Antioxidant activity (AOA) was decreased by 10% (1 kGy and 10% moisture) and increased by 13% (5 kGy and 10%) while significantly increased at all doses (at 12%) by 106%. Total flavonoids content and reducing power also affected significantly upon γ-irradiation at various moisture.Industrial relevanceThe present investigation is the first report revealing the impacts of moisture-mediated γ-irradiation of mung bean. Since γ-irradiation is a popular method for safe storage of food including legumes and cereals, the moisture content between 10 and 14% was considered safe for grain storage. But γ-irradiation of mung bean at these levels of moisture significantly changed the antioxidant potential. By selecting suitable moisture content and dose of γ-irradiation, the antioxidant potential of mung bean may be improved to get the maximum health benefit. Therefore, the legume processing industry can utilize these combinations (moisture and dose of irradiation) to improve the antioxidant properties of mung bean.     

Influence of postharvest gamma irradiation treatment on the content of bioactive compounds and antioxidant activity of fenugreek (Trigonella foenum–graceum L.) and spinach (Spinacia oleracea L.) leaves

Fenugreek and spinach leaves after irradiation in the dose range of 0.25–1.5 kGy were evaluated for the content of bioactive compounds and antioxidant activity using DPPH radical scavenging, ferric reducing ability power (FRAP), hydroxyl radical scavenging and ferrous ion chelating assays. Results of the study revealed that bioactive content except total ascorbic acid was significantly (p ≤ 0.05) higher in fenugreek compared to spinach. Data analysis revealed that gamma irradiation treatment significantly (p ≤ 0.05) enhanced the content of individual as well as total bioactive components of both vegetables. Positive correlation (r = 0.92) existed between gamma irradiation and total phenolics. The results of the antioxidant activity as determined by above mentioned assays revealed a significant (p ≤ 0.05) decrease in EC₅₀ values and a corresponding increase in antioxidant content and activity due to irradiation. Comparison of the increase in inhibition percentage, reducing power and chelating efficiency revealed that treatment of irradiation was significantly (p ≤ 0.05) effective in enhancing the ferric reducing power of both the vegetables (3.1–37.5% for fenugreek, 4.1–42.8% for spinach) and OH radical scavenging for spinach (1.5–22.4%) compared to fenugreek (0.78–13.1%). The present investigation suggested that postharvest radiation treatment to fenugreek and spinach has a potential to enhance their antioxidant content and activities, besides acting as a photo-sanitary treatment.Industrial relevanceThe increasing demand of convenience, wholesome and health promoting foods has resulted in search of new technologies to improve the shelf-life and at the same time preserve the nutritional quality. Prolonging postharvest storage, while enhancing the content of bioactive compounds will have a positive impact on both the industry and consumers. The present study demonstrated that postharvest radiation treatment of fenugreek and spinach can be used a novel approach to enhance their bioactive composition and antioxidant activity.