Amylose molecular fine structure dictates water-oil dynamics during deep-frying and the caloric density of potato crisps.

The fine structure of extractable amylose (E-AM) in potato flakes dictates oil uptake during the production of deep-fried crisps from dough made from the flakes, and thus their caloric density. High levels of short E-AM chains increase the extent of amylose crystallization during dough making and increase water binding. Time-domain proton NMR analysis showed that they also cause water to be released at a low rate during deep-frying and thus restrict dough expansion and, most importantly, oil uptake. X-ray micro-computed tomography revealed that this results in high thickness of the crisp solid matrix and reduced pore sizes. Thus, the level of short E-AM chains in potato flakes impacts amylose crystal formation, dough strength and expansion, as well as the associated oil uptake during deep-frying. Based on these results, we advise potato crisp manufacturers to source potato cultivars with high levels of short amylose chains for the production of reduced-calorie crisps and to make well-reasoned process adaptations to control the extractability of potato amylose.

Osteonecrosis of the jaw in patients with inflammatory bowel disease treated with tumour necrosis factor alpha inhibitors.

Previous reports have suggested a possible association between tumour necrosis factor alpha (TNF-α) inhibitors, used in the treatment of immune-mediated inflammatory diseases, and medication-related osteonecrosis of the jaw (MRONJ). However, a comprehensive assessment of the frequency and severity of MRONJ caused by these agents is lacking. The aim of this cohort study was to investigate the occurrence of MRONJ in a population of patients with inflammatory bowel disease (IBD) treated with TNF-α inhibitors at a tertiary care medical centre. A total of 2701 IBD patients under current or former treatment with TNF-α inhibitors were identified in an IBD registry covering the period 1994-2018. These patients were cross-matched with all patients diagnosed with MRONJ. This resulted in three patients with a definite diagnosis of MRONJ, without concomitant treatment with bisphosphonates. All three patients required surgical treatment with sequestrectomy. Mucosal healing occurred at 4-15 months and one patient developed recurrence. In conclusion, this study identified and described anti-TNF-α-related MRONJ occurring in a large cohort of IBD patients, and reported the severity and treatment strategies used.

Impact of mineral ions on the release of starch and gel forming capacity of potato flakes in relation to water dynamics and oil uptake during the production of snacks made thereof.

Potato flakes (PFs) are made by boiling, mashing and subsequent drying of steam peeled potatoes. Their cold-water swelling starch readily develops viscosity upon hydration. That potato starch amylopectin (AP) contains esterified phosphate groups results in rapid swelling and high viscosity of PF suspensions. This study is the first report on the impact of sodium, calcium and aluminum chloride on (i) the physicochemical properties of PFs and (ii) the water dynamics in relation to oil uptake in the production of deep-fried crisps made thereof. Adding 125 µmol cation/g PF dry matter (dm) of these salts to PF suspensions (8.0% dm) in a Rapid Visco Analyzer (RVA) decreased the peak viscosities by 5% (sodium chloride) and 20% (calcium or aluminum chloride). While monovalent cations shield the negative charges of the phosphate monoesters on the starch chains, divalent and trivalent cations bridge phosphate groups of adjacent AP molecules and thereby reduce swelling even further. Moreover, the latter ions result in up to 20% higher RVA cold paste viscosity readings even if they do not affect amylose (AM) aggregation. They thus enhance the gelation of PFs by AP bridging. For producing deep-fried crisps, PFs, emulsifier and maltodextrin were hydrated, mixed, sheeted into dough, and deep-fried. Including the above dosage of calcium ions in its recipe increased the specific strength of the dough sheet by about 15%. Time domain proton nuclear magnetic resonance analysis of dough sheets showed that these ions increase the rigidity of the starchy gel network while AM crystallization remains largely unaffected. This is evidence that ionic cross-linking of AP directly strengthens the dough sheet. Moreover, the calcium ions lowered the lipid content of the deep-fried crisps by about 5% due to stronger interaction of starch polymers with water. Ionic cross-linking of AP thus improves the gel forming capacity of PFs and strengthens the starchy gel network during manufacturing of potato-based snacks resulting in crisps with a significantly lower lipid content.

Impact of physical and enzymatic cell wall opening on the release of pre-gelatinized starch and viscosity forming potential of potato flakes.

Potato flakes (PFs) are used in instant foods. They contain pre-gelatinized starch which readily develops viscosity upon hydration. We here provide the first report on factors influencing their viscosifying potential. Swelling power (SP) (r = 0.719, p < 0.01) and mean particle size (r = -0.704, p < 0.05) mainly determine instant viscosity development of PF suspensions while short extractable extracellular amylose molecules [degree of polymerization between 150 and 1500 (EE-AM150-1500)] positively impact their cold paste viscosity (CPV) (r = 0.717, p < 0.01) in Rapid Visco Analyzer (RVA) models. Cell wall opening by ball milling or cellulase treatments increased PF SP resulting in up to 75% higher RVA peak viscosity readings. Furthermore, the release of EE-AM150-1500 molecules increased CPV by about 30% since they readily associated upon cooling. Partial cell wall opening thus improves the viscosifying potential of PFs and expands their applicability in instant foods.

Extractability and chromatographic characterization of wheat (triticum aestivum l.) bran protein.

About 70% of the protein for human consumption is derived from plants, with cereals as the most important source. Wheat bran protein has a more balanced amino acid profile than that of flour. We here for the first time report the amino acid, size exclusion, and SDS-PAGE profiles of bran Osborne protein fractions (OPFs). Moreover, we also investigated how OPFs are affected when physical barriers which entrap proteins in bran tissues are removed. Albumin/globulin is the most abundant OPF. It is richer in lysine and asparagine/aspartic acid than other OPF. Most bran albumin/globulin proteins have a molecular weight (MW) lower than 30 k and their chromatographic profiles differ from those of flour. The prolamin has high levels of proline and glutamine/glutamic acid. It is rich in proteins with a MW of 30 to 45 k and about 66 k reflecting contamination with gliadin from endosperm. The glutelin has high levels of glycine, proline, and glutamine/glutamic acid. Its protein is of intermediate and high MW with little protein with MW lower than 30 k. The high (MWs from 80 to 120 k) and low (MW around 45 k) MW glutenin subunits of flour are also present in bran. The glutelin of wheat endosperm is named glutenin. Ball milling releases albumin/globulin and glutelin but not prolamin. Not all glutelin was endosperm glutenin as a substantial part was entrapped in the aleurone cells.

Relative importance of moisture migration and amylopectin retrogradation for pound cake crumb firming.

Moisture migration largely impacts cake crumb firmness during storage at ambient temperature. To study the importance of phenomena other than crumb to crust moisture migration and to exclude moisture and temperature gradients during baking, crustless cakes were baked using an electrical resistance oven (ERO). Cake crumb firming was evaluated by texture analysis. First, ERO cakes with properties similar to those baked conventionally were produced. Cake batter moisture content (MC) was adjusted to ensure complete starch gelatinisation in the baking process. In cakes baked conventionally, most of the increase in crumb firmness during storage was caused by moisture migration. Proton nuclear magnetic resonance ((1)H NMR) showed that the population containing protons of crystalline starch grew during cake storage. These and differential scanning calorimetry (DSC) data pointed to only limited amylopectin retrogradation. The limited increase in amylopectin retrogradation during cake storage cannot solely account for the significant firming of ERO cakes and, hence, other phenomena are involved in cake firming.

Low resolution 1H NMR assignment of proton populations in pound cake and its polymeric ingredients.

Based on a model system approach, five different proton populations were distinguished in pound cake crumb using one dimensional low resolution (1)H NMR spectroscopy. In free induction decay (FID) measurements, proton populations were assigned to (i) non-exchanging CH protons of crystalline starch, proteins and crystalline fat and (ii) non-exchanging CH protons of amorphous starch and gluten, which are in little contact with water. In Carr-Purcell-Meiboom-Gill (CPMG) measurements, three proton populations were distinguished. The CPMG population with the lowest mobility and the FID population with the highest mobility represent the same proton population. The two CPMG proton populations with the highest mobility were assigned to exchanging protons (i.e., protons of water, starch, gluten, egg proteins and sugar) and protons of lipids (i.e., protons of egg yolk lipids and amorphous lipid fraction of margarine) respectively. Based on their spin-lattice relaxation times (T1), two dimensional (1)H NMR spectroscopy further resolved the two proton populations with the highest mobility into three and two proton populations, respectively.

Proteolytic activities in dormant rye (Secale cereale L.) grain.

Endoproteolytic, exoproteolytic, carboxypeptidase, aminopeptidase, and N-alpha-benzoyl-arginine-p-nitroanilide hydrolyzing activities were detected in 0.05 M sodium acetate buffer (pH 5.0) extracts of whole meal of the rye (Secale cereale L.) varieties Amando, Halo, and Humbolt. The proteolytic enzymes of Humbolt, the variety with the highest proteolytic activity, optimally hydrolyzed hemoglobin around pH 3.5 and 40-45 degrees C. In the different milling fractions of Humbolt, azocasein and hemoglobin hydrolytic activities were especially found in the bran and shorts. Proteolytic enzymes in the bran extract were concentrated in the 35-60% ammonium sulfate precipitate. Pepstatin A, an inhibitor of aspartic proteases, reduced approximately 88 and approximately 75% of the hemoglobin and azocasein hydrolyzing activities of this precipitate, respectively. Phenylmethanesulfonyl fluoride, an inhibitor of serine proteases, inhibited approximately 33% of both cited activities. Both rye and wheat storage proteins were degraded by Humbolt rye whole meal enzyme extract and the above-mentioned ammonium sulfate rye bran fraction in vitro. With the latter fraction digestion was more pronounced.

Specificity of a wheat gluten aspartic proteinase.

The substrate and peptide bond specificities of a purified wheat gluten aspartic proteinase (GlAP) are studied. GlAP shows maximum gluten hydrolysing activity at pH 3.0. At this pH, especially the wheat high molecular weight glutenin subunits (HMW-GS) and to a lesser extent the low molecular weight glutenin subunits and gliadins are hydrolysed. GlAP has no obvious effect on albumins and globulins. In its action on oxidised insulin B-chain, GlAP forms eight peptides and has high specificity for peptide bonds located between amino acid residues with large hydrophobic side chains (Leu, Phe, Tyr) but the peptide bond Glu13-Ala14 is also hydrolysed. Although structurally quite similar to a barley aspartic proteinase, the peptide bond specificity of GlAP towards oxidised insulin B-chain resembles slightly more that of a cardoon aspartic proteinase, cardosin B. HMW-GS 7, purified from cultivar Galahad-77, is rapidly hydrolysed by GlAP. N-Terminal amino acid sequence data show that GlAP cleaves at least one Met-Ile peptide bond at the end of the N-terminal domain and two Val-Leu peptide bonds in the repetitive domain of HMW-GS 7.