Real-Time Monitoring of Translocation, Dissipation, and Cumulative Risk of Maleic Hydrazide in Potato Plants and Tubers by Ion Exclusion Chromatography.

In this paper, a high-performance ion exclusion chromatographic (ICE) method was developed and applied for monitoring maleic hydrazide (MH) translocation in complex potato plant tissue and tuber matrices. After middle leaf uptake, most MH was trapped and dissipated in the middle leaf, and the rest was transported to other parts mainly through the phloem. Soil absorption significantly reduced the uptake efficiency of the root system, in which MH was partitioned to dissipate in root protoplasts or transfer through the xylem and persisted in the plant. Tuber uptake enabled MH to remain in the flesh and maintain stable levels under storage conditions, but during germination, MH was translocated from the flesh to the growing buds, where it dissipated through the short-day photoperiodic regime. The results demonstrated successful application of the ICE method and provided necessary insights for real-time monitoring of MH translocation behavior to effectively improve potato edible safety.

Effects of vacuum packaging storage of minimally processed cassava roots at various temperatures on microflora, tissue structure, starch extraction by wet milling and granule quality.

BACKGROUND: Vacuum package storage is commonly applied to reduce postharvest deterioration in minimally processed cassava roots. However, the influence of vacuum packaging conditions on root end-use quality is poorly understood. Hence, the effects of vacuum packaged storage at ambient, refrigerated and freezing temperatures on microflora, cassava tissue structure and starch extraction by wet milling were studied. RESULTS: Vacuum packaged storage temperature strongly affected cassava root quality. Minimal adverse effects were obtained with frozen storage. With refrigerated storage, there was negligible microbial growth but some disruption of the parenchyma cell wall structure suggestive of chilling injury. With ambient temperature storage, there was considerable Lactobacilli dominated fermentation. This caused substantial cell degradation, probably due to the production of extracellular cellulolytic and other cell wall degrading enzymes. A benefit of this cell wall breakdown was that it substantially improved starch extraction with wet milling from the stored cassava pieces; by 18% with pieces that had been ambient vacuum packaged and wet milled using a 2000 µm opening screen. However, ambient temperature storage resulted in some starch granule pitting due to the action of extracellular amylases from the fermenting microorganisms. CONCLUSION: The best vacuum packaging storage conditions for minimally processed cassava depends on application and cost. For short-term storage, refrigeration would be best for vegetable-type products. For several months storage, freezing is best. For wet milling applications, this could be combined with subsequent short-term ambient temperature storage as it improves starch extraction efficiency and could reduce distribution energy costs. © 2021 Society of Chemical Industry.

Germplasm evaluation to obtain inulin with high degree of polymerization in Mediterranean environment.

Long-chain length (DP) inulin-type fructans show pronounced beneficial effects to colon microbiota. In the past, cardoon roots for inulin production to fortify spaghetti gave very good results, but their harvest requires high costs. The aim of the work was to evaluate different types of inulin, extracted from cardoon roots and buds, topinambur tubers and chicory roots local populations in order to identify crops more suitable for high DP inulin production in Mediterranean environment. The inulin amount resulted in 115 (chicory), 390 (cardoon) and 550 g kg-1 of d.m. (topinambur). Both in cardoon roots and in topinambur tubers the DP was very high. With the aim to produce a functional food, substituting inulin in staple food tubers of topinambur could be a good alternative to cardoon roots, due to the biological cycle of the plant (annual vs poliennal), the lowest costs of harvest and the good amounts of high DP inulin.

Probabilistic health risk assessment of heavy metals in honey, Manihot esculenta, and Vernonia amygdalina consumed in Enugu State, Nigeria.

Honey is a nutritive fluid product of bees with an array of pharmacological/medicinal effects. As a natural product from honeybees, honey is regarded to be safe and free from any contaminants. Cassava tuber (Manihot esculenta)-based meal, Vernonia amygdalina (bitter leaf soup), and honey are common local cuisine in Nigeria. This is a human health risk assessment of heavy metals associated with the consumption of honey (Apis mellifera scutellata), cassava (Manihot esculenta), and bitter leaf (Vernonia amygdalina) in Enugu State, Nigeria. Concentrations of lead (Pb), Cd, As, Cu, Ni, Mn, Fe, Cr, and Fe in honey, soil, Manihot esculenta, and Vernonia amygdalina were determined using an atomic absorption spectrophotometer (AAS). The principal component analysis (PCA) was performed as a factor reduction technique among 12 factors (3 locations against 4 sources of heavy metals). The mean concentration of metals in honey, soil, Manihot esculenta, and Vernonia amygdalina ranged from 0.001 to 4.28 mg kg-1, from 0.0026 to 170.52 mg kg-1, from 0.012 to 80.63 mg kg-1, and from 0.0016 to 126.48 mg kg-1, respectively. Pb showed the highest carcinogenic risk with values of 3.18E-04-1.43E-01 in Vernonia amygdalina and 1.69E-04-3.47E-04 in Manihot esculenta for adults and children, respectively. In honey, Cd showed the highest carcinogenic risk with values of 1.26E-02-1.07E-01. About 51.5% of total cancer risk (TCR) was below 1E-04. Consumption of honey, Vernonia amygdalina, and Manihot esculenta in some urban parts of Enugu may pose some adverse health effects.

Potential Human Health Risk Assessment of Heavy Metals via Consumption of Root Tubers from Ogoniland, Rivers State, Nigeria.

This study was designed to investigate the concentration of heavy metals and their associated human health risk via consumption of root tubers cultivated in three major communities in Ogoniland, Rivers State, Nigeria. The concentration of heavy metals, especially, Cr and Pb in soil, indicates a moderate contamination (˃ 1.00 mg/kg) level. The concentrations of heavy metals in the root tubers Manihot esculenta, Colocasia esculenta, and Dioscorea alata harvested from Choba, Kpean, and Bodo City ranged from 0.20 ± 0.01-0.84 ± 0.04, 0.01 ± 0.001-0.09 ± 0.02, 0.01 ± 0.002-0.63 ± 0.04, 2.11 ± 0.03-11.8 ± 2.12, and 6.30 ± 1.18-118.6 ± 0.19 mg/kg for Cr, Pb, Ni, Mn, and Fe respectively, while Cd had the same value of 0.01 ± 0.001 mg/kg in the three samples across the three sites. The bio-accumulation factor (BAF) for Cd was ˃ 1. The estimated daily intake were below the FAO/WHO permissible limit, while the target hazard quotient (THQ) has a trend of Mn> Fe> Pb> Cd> Ni> Cr, and were ˂ 1 for all the sampling areas. The HI values for M. esculenta for children in Choba, Kpean, and Bodo City were ˃ 1, indicating that children among the local populace were susceptible to heavy metals health risks. The carcinogenic risk (CR) value of Cr indicates that there was appreciable lifetime cancer risk for Cr as the CR value in all the sampling sites were ˃ 10-4. Furthermore, CR values of Ni and Cd were also within the predicted lifetime risks of carcinogens. Heavy metal contamination of root tubers cultivated in Ogoniland may posed a great health risk to local populace especially for children via consumption of root tubers.

Soil-Plant Metal Relations in Panax notoginseng: An Ecosystem Health Risk Assessment.

This study features a survey of the content of heavy metals (Pb, Cd, Cr, As, Hg and Cu) in root and cultivation soils of Panax notoginseng (P. notoginseng), carried out in China's Yunnan Province. The average contents of Pb, Cd, Cr, As, Hg, and Cu in the soil were 61.6, 0.4, 102.4, 57.1, 0.3, and 35.1 mg·kg-1, respectively. The heavy metals' pollution indexes can be ranked as follows: As > Cd > Hg > Cu > Cr > Pb. The proportion of soil samples at slight, middle, strong, very strong, and extremely strong levels of potential environmental risk had values of 5.41%, 21.62%, 35.14%, 10.81%, and 27.03%, respectively. The potential environment risk index (RI) showed that 29.73% out of the total sample sites were above the level of strong and extremely strong. The ranges of Pb, Cd, Cr, As, Hg, and Cu content in tuber were 0.04-3.26, 0.04-0.33, 0.22-5.4, 0.10-1.8, 0.00-0.02, and 5.0-20.9 mg·kg-1, respectively. In combination with P. notoginseng consumption data, the estimated heavy metal daily intakes (EDIs) were 0.08-0.23, 0.006-0.019, 0.17-0.52, 0.04-0.12, 0.001-0.002, and 0.59-1.77 µg·kg-1·bw/day. All target hazard quotients (THQs) of individual elements and hazard indexes (HI) were less than one. The present study indicates that most of the P. notoginseng cultivation soil in the province of Yunnan presented slight and moderate ecological risk. Thus, more attention should be given to the heavy metals As, Cd, and Hg when selecting planting areas for the cultivation of P. notoginseng. Health risks associated with the intake of a single element or consumption of the combined metals through P. notoginseng are absent.

Modified Dietary Fiber from Cassava Pulp and Assessment of Mercury Bioaccessibility and Intestinal Uptake Using an In Vitro Digestion/Caco-2 Model System.

The ability of modified dietary fiber (MDF) generated from cassava pulp to modulate the bioaccessibility and intestinal absorption of heavy metals may be helpful to mitigate health risk associated with select foods including select fish high in methyl mercury. Using a coupled in vitro digestion/Caco-2 human intestinal cell model, the reduction of fish mercury bioaccessibility and intestinal uptake by MDF was investiaged. MDF was prepared from cassava pulp, a byproduct of tapioca production. The highest yield (79.68%) of MDF was obtained by enzymatic digestion with 0.1% α-amylase (w/v), 0.1% amyloglucosidase (v/v) and 1% neutrase (v/v). MDF and fish tissue were subjected to in vitro digestion and results suggest that MDF may reduce mercury bioaccessibility from fish to 34% to 85% compared to control in a dose-dependent manner. Additionally, accumulation of mercury from digesta containing fish and MDF was only modestly impacted by the presence of MDF. In conclusion, MDF prepared from cassava pulp may be useful as an ingredient to reduce mercury bioavailability from food such as fish specifically by inhibiting mercury transfer to the bioaccessibile fraction during digestion.

Heavy metals in vegetables sold in the local market in Jordan.

Heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn) in various vegetables (cabbage, green onion, lettuce, parsley, rocket, spinach, carrot, onion, potato and cauliflower) from the market in Jordan were measured using inductively coupled plasma-mass spectrometry. As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn ranged from 0.009-0.275 mg kg(-1) wet weight, 0.004-0.060 mg kg(-1), 0.003-0.401 mg kg(-1), 0.105-3.51 mg kg(-1), 0.15-1.15 mg kg(-1), 0.93-14.39 mg kg(-1), 0.044-0.702 mg kg(-1), 0.072-0.289 mg kg(-1) and 2.23-6.65 mg kg(-1), respectively. Parsley, followed by spinach, contained the highest concentration of heavy metals. Onion contained high levels of toxic heavy metals. The content of Cu in parsley and spinach and Pb in onion exceeded the Codex limits. However, the daily intake of heavy metals from the tested vegetables was lower than the maximum limits for allowable intake.

Assessment of Sauromatum guttatum lectin toxicity against Bactrocera cucurbitae.

Lectins are proteins that bind specifically to foreign glycans. Due to this binding property, these molecules have potential application as bioinsecticidal tools replacing conventional chemical insecticides. The present study involved purification of phytolectin from the tubers of Sauromatum guttatum by affinity chromatography on asialofetuin-linked silica matrix. The purity of the sample was checked by SDS-PAGE at pH 8.3. Purified lectin was incorporated in the artificial diet of a Dipteran model, Bactrocera cucurbitae at different concentrations (10, 20, 40, 60 and 80 µgml(-1)). The lectin significantly affected various developmental parameters that were studied. Percentage pupation and percentage emergence was reduced to 44 % and 7.9%, respectively, at 80 µgml(-1) concentration as compared to control (100%). LC50 of Sauromatum guttatum lectin was calculated to be 19.42 µgml(-1). Treatment of insect larvae with LC50 of Sauromatum guttatum lectin suppressed the activity of hydrolytic enzymes (esterases and acid phosphatases) and oxidative enzymes (superoxide dismutase and glutathione-S-transferase). Thus, with low LC50 and high mortality (approximately 92% at 80 µgml(-1)) of the insect larvae, Sauromatum guttatum lectin offers a possibility to engineer crop plants for improved and safer agriculture.

Defensive Armor of Potato Tubers: Nonpolar Metabolite Profiling, Antioxidant Assessment, and Solid-State NMR Compositional Analysis of Suberin-Enriched Wound-Healing Tissues.

The cultivation, storage, and distribution of potato tubers are compromised by mechanical damage and suboptimal healing. To investigate wound-healing progress in cultivars with contrasting russeting patterns, metabolite profiles reported previously for polar tissue extracts were complemented by GC/MS measurements for nonpolar extracts and quantitative (13)C NMR of interfacial solid suspensions. Potential marker compounds that distinguish cultivar type and wound-healing time point included fatty acids, fatty alcohols, alkanes, glyceryl esters, α,ω-fatty diacids, and hydroxyfatty acids. The abundant long-chain fatty acids in nonpolar extracts and solids from the smooth-skinned Yukon Gold cultivar suggested extensive suberin biopolymer formation; this hypothesis was supported by high proportions of arenes, alkenes, and carbonyl groups in the solid and among the polar markers. The absence of many potential marker classes in nonpolar Atlantic extracts and interfacial solids suggested a limited extent of suberization. Modest scavenging activities of all nonpolar extracts indicate that the majority of antioxidants produced in response to wounding are polar.

New food from a potato somatic hybrid: nutritional equivalence and safety assessment by a feeding study on rats.

BACKGROUND: Potato tubers from the STBd somatic hybrid line that exhibited improved tolerance to salinity and resistance to fungal and PVY infections were characterised. They were compared for their chemical composition to the Spunta variety produced by conventional agronomic practices. This study aimed to compare nutritional value and safety by feeding rats with STBd or commercial tubers added to the standard diet (20/80 w/w). RESULTS: The analysis of soluble sugar, fat, fibre and ash content of tubers did not reveal any significant differences between the hybrid line and the control Spunta variety. Small differences were observed in dry matter, starch and protein content of hybrid potatoes in comparison to controls. However, all values were within normal ranges reported in the literature. The feeding study on rats showed that overall health, weight gain, food consumption, morphological aspects and weights of organs were comparable between rat groups fed the STBd hybrid and the Spunta variety. CONCLUSION: Taken together, 28 days of consumption of STBd hybrid potato did not exert any adverse effect on rats compared with commercial Spunta potato. The STBd potato line was therefore considered to be as safe for food utilisation as the commercial variety.

A GC-MS-based metabolomics study on the tubers of commercial potato cultivars upon storage.

Using gas chromatography-mass spectrometry (GC-MS) as a system for the detection of amino acids, organic acids, sugars, sugar alcohols, and fatty acids, we characterised six commercial potato cultivars (Hópehely, Katica, Lorett, Somogyi kifli, Vénusz Gold, and White Lady) with different pedigrees, starch contents, cooking types, and dormancy periods, in five developmental stages from harvest to sprouting. The tubers were stored at 20-22°C in the dark. The metabolite data were subjected to principal component analysis. No correlation between metabolite contents of freshly harvested tubers and starch content or cooking type of the cultivars was detected. The storage decreased the fructose and sucrose and increased the proline concentrations of tubers. Irrespective of the length of dormancy a substantial difference in metabolite composition at each time point upon storage was detected in each cultivar except Somogyi kifli, the only cultivar amongst those tested with a pure Solanum tuberosum origin and A cooking type.

Probiotic characterization of potential hydrolases producing Lactococcus lactis subsp. lactis isolated from pickled yam.

The aim of this study was to characterize potential probiotic strain co-producing α-amylase and ß-galactosidase. Sixty-three strains, isolated from pickle samples were screened for their hydrolase producing capacity by utilizing different starches as carbon source. One out of 63 strains, isolated from traditionally fermented pickled yam showing maximum hydrolase activity (α-amylase (36.9 U/ml) and ß-galactosidase (42.6 U/ml)) within a period of 48 hours was identified as Lactococcus lactis subsp. lactis. Further, it was assessed for the probiotic characteristics under gastrointestinal conditions like acidic, alkaline, proteolytic enzymes, bile stress and found to exhibit tolerance to these stresses. The therapeutic potential of the isolate is implicated because of its antagonistic effect against enteric foodborne pathogens (Salmonella typhimurium, Escherichia coli 0157:H7, Staphylococcus aureus, Yersinia enterocolitica and Aeromonas hydrophila). The results of this study entail a potential applicability of the isolate in developing future probiotic foods besides the production of industrially significant hydrolases.

Nitrate and nitrite levels in commonly consumed vegetables in Hong Kong.

Levels of nitrate and nitrite in 73 different vegetables, a total of 708 individual samples grouped into leafy, legumes, root and tuber, and fruiting vegetables, which are traded mainly in Hong Kong, were measured. Where available, five samples of each vegetable type were purchased from different commercial outlets during the winter of 2008 and summer of 2009. Levels of nitrate and nitrite were determined by ion chromatography and flow injection analysis, respectively. Nitrate and nitrite levels of all samples ranged <4-6300 and <0.8-9.0 mg kg⁻¹, respectively. Nitrate concentrations for the different groups, in descending order, were leafy > root and tuber > fruiting and legume vegetables. More than 80% of vegetables had mean nitrate concentrations less than 2000 mg kg⁻¹, but mean nitrate concentrations of three types of leafy vegetables, namely Chinese spinach, Shanghai cabbage and Chinese white cabbage, were >3500 mg kg⁻¹. On the other hand, nitrite concentrations were generally low - <1 mg kg⁻¹ on average. Nitrate in vegetables (i.e. Chinese flowering cabbage, Chinese spinach and celery) can be reduced significantly (12-31%) after blanching for 1-3 min, but not after soaking.

A novel ex vivo skin model for the assessment of the potential transcutaneous anti-inflammatory effect of topically applied Harpagophytum procumbens extract.

Using ex vivo skin as a model, this work tested the hypothesis that the major pharmacologically active components of topically applied Harpagophytum procumbens (H. procumbens) can elicit anti-inflammatory responses in deeper tissues post-transcutaneous delivery. Using Franz-type diffusion cells, ethanol extract of powdered H. procumbens tuber was dosed onto freshly excised porcine skin. After 24 h the receptor phase was recovered, analysed for the major glycosides of DC, then used directly to dose further freshly excised skin membranes. After 6h the skin was recovered and probed for the expression of the three major enzymes involved in the inflammatory factors: cyclooxygenase (COX-2) and its product prostaglandin E2 (PGE-2), lipoxygenase (5-LOX), and inducible nitric oxide (iNOS), using immunocytochemistry and Western blotting analyses. It was found that the receptor phase at 24 h contained (0.8, 25, 1.8, 3 x 10(-3)) micromol mL(-1) of harpagoside, harpagide, verbascoside, 8-O-p-coumaroyl-harpagide, respectively. When applied to skin, this solution effectively inhibited the expression of COX-2 and its product PGE-2. However, it did not have a significant effect on either 5-LOX or iNOS compared to control samples (PBS only). These data support the hypothesis that the transcutaneous delivery of H. procumbens can treat inflammation in deeper tissues such as in arthritis. Moreover, a novel ex vivo model has been described for assessing the potential anti-inflammatory activity of permeants delivered to deeper subcutaneous regions.

Modification of the health-promoting value of potato tubers field grown under drought stress: emphasis on dietary antioxidant and glycoalkaloid contents in five native andean cultivars (Solanum tuberosum L.).

The effects of drought stress on dietary antioxidant and glycoalkaloid contents in potato tubers were investigated using a selection of five native Andean cultivars. Both freshly harvested and 4 month-stored tubers were analyzed. Responses to drought stress were highly cultivar-specific. The antioxidant contents of the yellow tuber-bearing cultivars (Sipancachi and SS-2613) were weakly affected by the drought treatment, whereas the pigmented cultivars demonstrated highly cultivar-dependent variations. A drastic reduction of anthocyanins and other polyphenols was revealed in the red- (Sullu) and purple-fleshed (Guincho Negra) cultivars, whereas an increase was shown in the purple-skinned and yellow-fleshed cultivar (Huata Colorada). The hydrophilic antioxidant capacity (evaluated by Folin-Ciocalteu and H-oxygen radical absorbance capacity assays) was highly correlated with the polyphenol content and followed, therefore, the same behavior upon drought. Carotenoid contents, including beta-carotene, as well as vitamin E, tended to increase or remain stable following drought exposure, except for the cultivar Sullu, in which the level of these lipophilic antioxidants was decreased. Vitamin C contents were not affected by drought with the exception of Guincho Negra, in which the level was increased. These variations of health-promoting compounds were associated with increased or stable levels of the toxic glycoalkaloids, alpha-solanine and alpha-chaconine. Storage at 10 degrees C for 4 months tended to decrease the concentrations of all dietary antioxidants, except those of vitamin E. This storage also reduced the drought-induced variations observed in freshly harvested tubers. These results were discussed in terms of their implications for human diet and health as well as in plant stress defense mechanisms.