Effect of autoclaving on the formation of resistant starch from two Nigeria Cassava (Manihot esculenta) varieties

Open Access Journal; Published online: 31 Aug 2018This study evaluated the effect of autoclaving process on the production of resistant starch (RS) from cassava starch. RS was prepared by debranching, autoclaving and storage of cassava starch from two Nigeria varieties (TMS 30572 and TMS 98/0581). Starch suspensions were prepared with different starch water ratios (1:1; 1:3; and 1:5), debranched with isoamylase, autoclaved at 110 and 121◦C for four heat and cool cycles, stored under refrigeration and freezing condition for 48 h. Debranching process increased RS by about 73-78%. Higher RS was obtained at higher temperature and with significant difference (p<0.05) from each other. RS increased with storage time from 6.23 to 9.60 and 22.40 to 25.77 g/100 g for undebranched and debranched samples, respectively, after 48 h. This study indicated the potentials of these Nigeria cassava varieties in the production of RS which could serve as functional food

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification. Funding: UK Research and Innovation and National Institute for Health Research

Isolation, fractionation and characterisation of proteins from Mucuna bean

The chemical composition and fractional distribution of protein isolates prepared from species of Mucuna bean were studied. Using six different extraction media, the yield of protein based on the Kjeldahl procedure varied from 8% to 34%, and the protein content varied from 75% to 95%. When the yields were high, the colour of the isolates generally tended to be dark and unsatisfactory. Hence, the use of chemical treatments and high pressure processing were explored. The solubility maxima for the protein isolates in water were found to occur at pH values of 2.0 and 11.0, while the pH corresponding to minimum solubility (i.e. isoelectric region) occurred at pH values of 4.0 and 5.0. The total essential amino acid in the isolates ranged from 495 to 557 mg g(-1) protein, which compares favourably with the recommended level for pre-school and school children. Methionine and cysteine were the limiting amino acids. A key nutritional attribute of the protein isolates was its high lysine content. The isolate can therefore complement cereal-based foods which are deficient in lysine. The proteins mainly consisted of albumins, glutelins and globulins. Prolamins were only present in trace concentration (< 0.3%). Gel filtration chromatograms of the isolates indicated the presence of major protein fractions with molecular weights of 40 and 15 kDa, while gel electrophoresis (SDS-PAGE) indicated a major broad zone with molecular weights of 36 +/- 7 and 17.3 +/- 13 kDa. (c) 2006 Elsevier Ltd. All rights reserved

Determination of an effective maturity index for white yam (Dioscorea rotundata)

Whole small tubers and setts from 15 genotypes of white yam (Dioscorea rotundata) at their post-dormant stage were planted at the beginning of the rainy season in 2003 and 2004. Harvesting was done at monthly intervals from three months after vine emergence (MAVE) till when there was senescence of foliage. Dry matter, sugar and starch contents of both the leaves and yam tubers were monitored during growth to determine an indicator for maturity that could indicate the best time to harvest the tuber. The dry matter content of leaves increased steadily from 3 MAVE (range of 19.31–24.56%) to 5 MAVE (range of 20.86–43.28%). Sharp increase was noticed between 5 MAVE when yellowing of lower leaves was observed, a sign of on-set of senescence, and 6 MAVE (range of 78.16–90.49%), when the leaves were dry and brown. Dry matter content values increased steadily in the tubers with age of plant till senescence of foliage took place. The sugar content of leaves declined between 3 and 4 MAVE, rose at 5 MAVE and dropped again at the time of foliage senescence (6 MAVE). An initial sharp decline in sugar content of the yam tuber of most of the genotypes was observed from 3 to between 4 and 5 MAVE before rising again at 6 MAVE. The starch content of leaves decreased between 3 and 5 MAVE and increased again at 6 MAVE. Dry matter content of leaves could be used as rapid index for determining tuber maturity. The starch content of leaves could also serve as an indicator for determining tuber maturity since the tuber is matured when minimum starch content is obtained in the leaves, which coincided with the time that yellowing of lower leaves of the plant was observed

Effect of steam cooking and storage time on the formation of resistant starch and functional properties of cassava starch

In this study, resistant starch (RS), type 3, was prepared by debranching, steam cooking and storage of cassava native starch obtained from two Nigeria varieties (TMS 30572 and 98/0581). The native starch samples were debranched with isoamylase enzyme, steam cooked both at atmospheric and high pressure (15 psi) and stored under refrigeration (5–7°C) and freezing condition (−18°C) for 48 h. The effects of these processing conditions on the formation of RS were determined. The debranching process increased the resistant starch contents of the cassava starch to about 70% over the undebranched samples. The RS contents from the steam cooking process ranged between 5.99 and 19.55 g/100 g. The highest value was obtained in TMS 30572 debranched and steam cooked at atmospheric pressure while the least RS was obtained from TMS 98/0581 undebranched but steam cooked at atmospheric pressure. The RS contents increased with increase in storage time with refrigeration having a higher resistant starch contents compared with freezing. Formation of RS decreased the Swelling Power, Water Absorption Index and Water Solubility Index of the Starch while the Syneresis Value increased. This study showed that cassava starch is suitable for isoamylase debranching, and RS formation