Determination of Ca, P, K, Na, and Mg in Australian Retail Pasteurised Milk Using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP OES).

A rapid and simple inductively coupled plasma atomic emission spectrometry (ICP OES) method was developed and validated for the determination of macroelements including calcium (Ca), phosphorus (P), potassium (K), sodium (Na), and magnesium (Mg) in Australian retail pasteurised milk. The milk samples were digested using the mixture of 70% HNO3 and 30% H2O2 (2 : 1, v/v) in an open-tube digester block at 120°C for 4 h. The validated ICP OES method showed good linearity for all elements (R 2 > 0.9993). The method limits of quantification (LOQ) for Ca, P, K, Na, and Mg were 19.85, 8.97, 100.8, 41.92, and 11.56 µg·g-1, respectively. Recoveries were in the range of 91.54-116.0%. Repeatability and interday reproducibility expressed as the relative standard deviation (% RSD) was below 5.0%. The contents of macroelements in 6 retail pasteurised milk samples were between 1099.32 and 1348.65 µg·g-1 (Ca), 914.01 and 1091.21 µg·g-1 (P), 1362.76 and 1549.74 µg·g-1 (K), 288.89 and 323.22 µg·g-1 (Na), and 97.62 and 110.57 µg·g-1 (Mg). Principal component analysis (PCA) revealed that retail pasteurised milk samples were distinctly separated into four groups on the first two principal components (PCs). The difference in the macroelement content between milk brands might be affected by milk regions.

Effect of lecithin on the complexation between different botanically sourced starches and lauric acid.

This research investigated the effect of lecithin on the complexation of lauric acid with maize starch, potato starch, waxy maize starch, and high amylose maize starch. Rapid visco analysis showed that lecithin altered the setback pattern of potato starch-lauric acid and maize starch-lauric acid mixtures but not waxy maize starch-lauric acid. Further investigation, including differential scanning calorimetry, complex index, and X-ray diffraction, showed that lecithin enhanced the complexation of maize starch, potato starch, and high amylose maize starch with lauric acid. Fourier transform infrared and Raman spectroscopy revealed increasingly ordered structures formed in maize starch-lauric acid-lecithin, potato starch-lauric acid-lecithin, and high amylose maize starch-lauric acid-lecithin systems compared to corresponding binary systems. These highly ordered complexes of maize starch, potato starch, and high amylose maize starch also demonstrated greater resistance to in vitro enzymatic hydrolysis. Waxy maize starch complexation however remained unaffected by lecithin. The results of this study show that lecithin impacts complexation between fatty acids and native starches containing amylose, with the starch source being critical. Lecithin minimally impacted the complexation of low amylose starch and fatty acids.

Fatty acid profiling of Western Australian pasteurised milk using gas chromatography-mass spectrometry.

The fatty acid composition of Western Australian commercial pasteurised milk was profiled using gas chromatography-mass spectrometry (GC-MS). A total of 31 fatty acids (FA) were identified in the milk samples. The majority of FA were medium-chain fatty acids (MCFA) with 6-13 carbon atoms and long-chain fatty acids (LCFA) with 14-20 carbon atoms. The results of principal component analysis (PCA) showed significant differences in the levels of MCFA and LCFA in the different milk samples. The levels of MCFA and LCFA ranged from 10.09 % to 12.12% and 87.88% to 89.91% of total FA, respectively. C10:0 and C12:0 were the major components of MCFA comprising 3.46% and 4.22% of total FA, while C16:0 and C18:1 (cis 9-octadecenoic acid) represented the majority of LCFA with the levels of 26.18% and 23.34% of total FA, respectively. This study provides new insight into the FA composition of Western Australian pasteurised milk and differences in FA profiles which influence human health.

Enzymatic browning: The role of substrates in polyphenol oxidase mediated browning.

Enzymatic browning is a biological process that can have significant consequences for fresh produce, such as quality reduction in fruit and vegetables. It is primarily initiated by polyphenol oxidase (PPO) (EC 1.14.18.1 and EC 1.10.3.1) which catalyses the oxidation of phenolic compounds. It is thought that subsequent non-enzymatic reactions result in these compounds polymerising into dark pigments called melanins. Most work to date has investigated the kinetics of PPO with anti-browning techniques focussed on inhibition of the enzyme. However, there is substantially less knowledge on how the subsequent non-enzymatic reactions contribute to enzymatic browning. This review considers the current knowledge and recent advances in non-enzymatic reactions occurring after phenolic oxidation, in particular the role of non-PPO substrates. Enzymatic browning reaction models are compared, and a generalised redox cycling mechanism is proposed. The review identifies future areas for mechanistic research which may inform the development of new anti-browning processes.

Starch granule size: Does it matter?

Nature has developed starch granules varying in size from less than 1 µm to more than 100 µm. The granule size is an important factor affecting the functional properties and the applicability of starch for food and non-food applications. Within the same botanical species, the range of starch granule size can be up to sevenfold. This review critically evaluated the biological and environmental factors affecting the size of starch granules, the methods for the separation of starch granules and the measurement of size distribution. Further, the structure at different length scales and properties of starch-based on the granule size is elucidated by specifying the typical applications of granules with varying sizes. An amylopectin cluster model showing the arrangement of amylopectin from inside toward the granule surface is proposed with the hypothesis that the steric hindrance for the growth of lamellar structure may limit the size of starch granules.

Noodles Made from High Amylose Wheat Flour Attenuate Postprandial Glycaemia in Healthy Adults.

Previous research has not considered the effect of high amylose wheat noodles on postprandial glycaemia. The aim of the study is to investigate the effect of consumption of high amylose noodles on postprandial glycaemia over 2-h periods by monitoring changes in blood glucose concentration and calculating the total area under the blood glucose concentration curve. Twelve healthy young adults were recruited to a repeated measure randomised, single-blinded crossover trial to compare the effect of consuming noodles (180 g) containing 15%, 20% and 45% amylose on postprandial glycaemia. Fasting blood glucose concentrations were taken via finger-prick blood samples. Postprandial blood glucose concentrations were taken at 15, 30, 45, 60, 90 and 120 min. Subjects consuming high amylose noodles made with flour containing 45% amylose had significantly lower blood glucose concentration at 15, 30 and 45 min (5.5 ± 0.11, 6.1 ± 0.11 and 5.6 ± 0.11 mmol/L; p = 0.01) compared to subjects consuming low amylose noodles with 15% amylose (5.8 ± 0.12, 6.6 ± 0.12 and 5.9 ± 0.12 mmol/L). The total area under the blood glucose concentration curve after consumption of high amylose noodles with 45% amylose was 640.4 ± 9.49 mmol/L/min, 3.4% lower than consumption of low amylose noodles with 15% amylose (662.9 ± 9.49 mmol/L/min), p = 0.021. Noodles made from high amylose wheat flour attenuate postprandial glycaemia in healthy young adults, as characterised by the significantly lower blood glucose concentration and a 3.4% reduction in glycaemic response.

Review of the Sensory and Physico-Chemical Properties of Red and White Wheat: Which Makes the Best Whole Grain?

Establishing sensory and physico-chemical differences between products made from red and white wheat may guide the choice of wheat for use in whole grain and high fibre products. As sensory acceptance is key to consumption, this scoping review aimed to document sensory and physico-chemical research demonstrating quantitative differences in red and white wheat and the associated bran. The following databases were systematically searched following the PRISMA protocol: PubMed, Medline, Scopus, CINHAL and ScienceDirect (1990-2019). Of 16 studies, 13 were sensory studies with 529 participants (six of which included quantitative analysis) and three additional quantitative studies. Overall, 10 studies were in favour of white wheat (seven sensory studies, two focused on quantitative analysis and two with additional quantitative studies). Whole grain (wholemeal) bread, pita bread, crackers, noodles, tortillas, flour, intact grains and bran were examined. Aside from the seed coat colour, levels of bound versus free phenolic compounds and polyphenol oxidase activity appeared most responsible for the differences in red and white wheat. Ensuring the sample size for sensory studies are large enough to detect between-group preferences and linking to physico-chemical analysis are recommended. Attention to blinding techniques in sensory testing and use of food products realistically and consistently prepared with commercial potential are also suggested. This scoping review provides confidence in preference for white wheat for whole grain products, particularly for breads, tortillas and in the choice of white wheat for products suitable for the Asian market.

Application of ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (Orbitrap™) for the determination of beta-casein phenotypes in cow milk.

The objective of this study was to determine the ß-CN phenotypes in cow milk collected from HF and cross-bred HF dairy cattle in Phu Dong, Vietnam. In total, 85 samples of raw milk were collected from 85 individual cows. Beta-casein (ß-CN) phenotypes in cow milk were determined using ultra-high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS). The results showed that three ß-CN variants A1, A2 and I were detected and identified in the milk samples. Five ß-CN phenotypes A1A1, A1A2, A1I, A2A2 and A2I were found with percentages of 0.035, 0.400, 0.059, 0.482 and 0.024, respectively. The higher proportion of ß-CN phenotype A2A2 compared to other phenotypes was expected because of changes in dairy cow breeding in Phu Dong, Vietnam.

Effect of PolyGlycopleX (PGX) Consumption on Blood Lipid Profiles in Healthy, Low CVD Risk Overweight Adults.

Raised blood lipid levels are associated with a risk of a cardiovascular disease (CVD). Moderate reductions in several CVD factors such as total, low-density lipoprotein (LDL) cholesterol and non-high-density lipoprotein (non-HDL) cholesterol concentrations may be more effective in reducing overall risk than a major reduction in just one. A blind, randomised controlled trial was conducted with 120 healthy overweight (BMI 25⁻30) adults aged 25⁻70 years who were non-smokers, not diabetic and of low risk of cardiovascular disease, as assessed by the Framingham risk equation. Participants consumed 4.5 g PolyGlycopleX (PGX) as softgel capsules (PGXS) or 5 g PGX granules (PGXG) or 5 g rice flour (RF) with meals three times a day for 12 weeks. Total, LDL and non-HDL cholesterol were all significantly reduced (-6%, -5% and -3.5%, respectively) post the PGX granule treatment; however, PGX in softgel capsule form did not affect blood lipid profiles. Daily consumption of PGX granules in overweight low CVD risk adults produced lipid changes indicating a CVD preventative benefit.

Degradation of ß-casomorphins and identification of degradation products during yoghurt processing using liquid chromatography coupled with high resolution mass spectrometry.

Liquid chromatography-high resolution mass spectrometry (LC-HRMS) was used to investigate the degradation of ß-casomorphin 5 (ß-CM5) and ß-casomorphin 7 (ß-CM7) by Streptococcus thermophilus and/or Lactobacillus delbrueckii ssp. bulgaricus, and to identify the degradation products forming during yoghurt processing. Bovine UHT milk was fermented with: (i) a single strain of L. delbrueckii ssp. bulgaricus, (ii) a single strain of S. thermophilus and (iii) the mixture of S. thermophilus and L. delbrueckii ssp. bulgaricus to pH4.5 and then stored at 4°C for 1 and 7days. Results showed that L. delbrueckii ssp. bulgaricus and/or S. thermophilus completely degraded ß-CM5 and ß-CM7 upon fermentation to pH4.5 and degradation products were significantly influenced by bacteria strains and storage time. Four peptides, ß-CNf60-61 (YP), ß-CNf62-63 (FP), ß-CNf64-66 (GPI) and ß-CNf62-66 (FPGPI) were tentatively identified through high resolution MS/MS experiments; however, it was not possible to confirm if either milk protein or ß-casomorphins was a source releasing these peptides. Nonetheless, in this study peptides YP and GPI were released by L. delbrueckii ssp. bulgaricus. This is the first time GPI has been identified and thus future investigation of its bioactivity is warranted.

Evaluation of a Commercial Sandwich Enzyme-Linked Immunosorbent Assay for the Quantification of Beta-Casomorphin 7 in Yogurt Using Solid-Phase Extraction Coupled to Liquid Chromatography-Tandem Mass Spectrometry as the "Gold Standard" Method.

This study investigated beta-casomorphin 7 (BCM7) in yogurt by means of LC-tandem MS (MS/MS) and enzyme-linked immunosorbent assay (ELISA) and use LC-MS/MS as the "gold standard" method to evaluate the applicability of a commercial ELISA. The level of BCM7 in milk obtained from ELISA analysis was much lower than that obtained by LC-MS/MS analysis and trended to increase during fermentation and storage of yogurt. Meanwhile, the results obtained from LC-MS/MS showed that BCM7 degraded during stages of yogurt processing, and its degradation may have been caused by X-prolyl dipeptidyl aminopeptidase activity. As a result, the commercial sandwich ELISA kit was not suitable for the quantification of BCM7 in fermented dairy milk.

Consumer attitudes and misperceptions associated with trends in self-reported cereal foods consumption: cross-sectional study of Western Australian adults, 1995 to 2012.

BACKGROUND: The reasons for low adherence to cereal dietary guidelines are not well understood but may be related to knowledge, attitudes, beliefs and perceived barriers. This study aims to assess trends in cereal foods consumption, intention to change and factors associated with intake among Western Australian (WA) adults 18 to 64 years. METHOD: Cross-sectional data from the 1995, 1998, 2001, 2004, 2009, and 2012 Nutrition Monitoring Survey Series involving 7044 adults were pooled. OUTCOME VARIABLES: types and amount of cereals (bread, rice, pasta, and breakfast cereal) eaten the day prior. Attitudes, knowledge, intentions, weight status and sociodemographic characteristics were measured. Descriptive statistics, multiple binary logistic and multinomial logistic regressions assess factors associated with consumption. RESULTS: Bread (78%) was the most commonly consumed cereal food. The proportion eating bread decreased across survey years (Odds Ratio OR = 0.31; 95% Confidence Interval; 0.24-0.40 in 2012 versus 1995), as did the amount (4.1 slices of bread in 1995 to 2.4 in 2012). The odds of consuming whole-grain cereal foods increased since 2009 (OR = 1.27; 1.02-1.58 versus 1995 p < 0.05). The likelihood of trying to eat less cereal food in the past year was greater in 2012 compared to 1995 (Relative Risk Ratio RRR 10.88; 6.81-17.4). Knowledge of cereal recommendations decreased over time (OR = 0.20; 0.15-0.27 in 2012 versus 1995 p < 0.001). Overweight and obese respondents were more likely than healthy weight respondents to have tried to eat less cereals (RRR 1.65; 1.22-2.24 and 1.88; 1.35-2.63 respectively). 'I already eat enough' was the main barrier (75% in 1995 to 84% in 2012 (p < 0.001)). CONCLUSIONS: WA adults are actively reducing the amount of cereal foods they eat and intake is associated with a misperception of adequacy of intake. Nutrition intervention is needed to increase awareness of the health benefits of cereal foods, particularly whole-grains, and to address barriers to incorporating them daily. TRIAL REGISTRATION: Not applicable.

Response to Comments by Vuksan V. et al., Nutrients 2017, 9, 398, Regarding an Article by Solah V.A. et al., Nutrients 2017, 9, 149.

n/a.

Erratum: Effect of Fibre Supplementation on Body Weight and Composition, Frequency of Eating and Dietary Choice in Overweight Individuals Nutrients 2017, 9, 149.

n/a.

Effect of incorporating finger millet in wheat flour on mixolab behavior, chapatti quality and starch digestibility.

Wheat and finger millet flour (two cultivars) were blended in the ratio (3:1) to form a composite flour and its dough properties were studied on the mixolab. The chapatti making and digestibility behavior of the composite flour was also investigated. The wheat finger millet (WFM) flour blend displayed up to 30.7% higher total phenolic content (TPC), 38.2% higher total flavonoid content (TFC) and 75.4% higher antioxidant activity (AOA) than the wheat flour. Chapattis prepared from the composite blends exhibited lower retrogradation as evident by the mixolab retrogradation index, higher values of soluble starch and soluble amylose in stored chapatti. The slowly digestible starch (SDS) correlated positively (R=0.816, p<0.05) with TPC and water absorption correlated positively (R=0.995, p<0.05) with damage starch content. The chapattis made from the composite flour had higher SDS and resistant starch (RS) values demonstrating potential as a food with functional characteristics.

The influence of ethnicity and glucose tolerance status on subjective hunger sensations and prospective food intake in overweight and obese Asian and European Australians.

AIMS: To examine the influence of ethnicity and glucose tolerance status on subjective sensations and food intake in overweight/obese Asian and European Australians. METHODS: 18 Asians and 26 Europids were classified as normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) based on serial measures of finger-prick glucose following an oral glucose tolerance test (OGTT). Subjective sensations of hunger and satiety were measured before and every 15min after the OGTT using a visual analogue scale (VAS). Food intake was measured covertly from consumption of a buffet style lunch and from self-maintained 24h food records. All serial measurements were converted into total area under the curve (TAUC) and comparisons adjusted for age, fat and fat-free mass. RESULTS: There was a significant difference interaction between ethnicity (ETH) and glucose tolerance (GTT) for subjective fullness, desire for food and prospective food intake. IGT Asians had significantly greater sensations of fullness, but lesser prospective food and desire to eat, as compared to other groups. However there were no differences in calorie and macronutrient intake at buffet lunch or over 24-h. CONCLUSION: Interactions between ethnicity and glucose tolerance status in subjective sensations did not transcribe to differences in prospective food intake.

BMI is Associated with the Willingness to Record Diet with a Mobile Food Record among Adults Participating in Dietary Interventions.

Image-based dietary assessment methods have the potential to address respondent burden and improve engagement in the task of recording for dietary interventions. The aim of this study was to assess factors associated with the willingness of adults to take images of food and beverages using a mobile food record (mFR) application. A combined sample of 212 young adults and 73 overweight and obese adults completed a 4-day mobile food record on two occasions and a follow-up usability questionnaire. About 74% of participants stated they would record using the mFR for a longer period compared with a written record (29.4 ± 69.3 vs. 16.1 ± 42.6 days respectively; p < 0.0005). Multivariable logistic regression was used to identify those who were more likely to record mFR in the top tertile (≥14 days). After adjusting for age and gender, those with a BMI ≥ 25 were 1.68 times more likely (Odds Ratio 95% Confidence Interval: 1.02-2.77) than those with BMI < 25 to state a willingness to record with the mFR for ≥ 14 days. The greater willingness of overweight and obese individuals to record dietary intake using an mFR needs further examination to determine if this translates to more accurate estimates of energy intake.

Effect of Fibre Supplementation on Body Weight and Composition, Frequency of Eating and Dietary Choice in Overweight Individuals.

Fibre supplementation can potentially reduce energy intake and contribute to weight loss. The mechanism may be reduced frequency of eating, resulting in reduced food consumption. The objective of this research was to determine the effectiveness of fibre supplementation with PolyGlycopleX® (PGX®), on body weight and composition, frequency of eating and dietary intake in 118 overweight adults. In a three-arm, parallel, blind, randomised controlled trial participants were randomised to one of three groups; 4.5 g PGX as softgels (PGXS), 5 g PGX granules (PGXG) or 5 g rice flour (RF) control. Prior to supplementation and at 12 weeks, participants captured before and after images of all food and beverages consumed within 4 days using a mobile food record app (mFR). The mFR images were analysed for food group serving sizes and number of eating occasions. In the PGXG group, per-protocol analysis [corrected] analysis showed there was a significant reduction in waist circumference (2.5 cm; p = 0.003). Subgroup analysis showed that PGXG supplementation at the recommended dose resulted in a reduction in body weight (-1.4 ± 0.10 kg, p < 0.01), body mass index (BMI) reduction (-0.5 ± 0.10, p < 0.01), reduced number of eating occasions (-1.4 ± 1.2, p < 0.01) and a reduced intake of grain food (-1.52 ± 1.84 serves, p = 0.019). PGXG at the recommended dose resulted in a reduction in weight and BMI which was significantly greater than that for RF (p = 0.001). These results demonstrate the potential benefits of PGX fibre in controlling frequency of eating and in weight loss.

Recruitment of older adults with type 2 diabetes into a community-based exercise and nutrition randomised controlled trial.

BACKGROUND: Recruitment of participants into long-term community-based lifestyle intervention trials, particularly adults with a chronic disease, is often slow and challenging. Currently there is limited data on successful recruitment strategies suitable for older adults with type 2 diabetes into community-based exercise and nutrition programs, and no information on cost estimates associated with such recruitment. The aim of this report is to describe the recruitment strategies used and the success of each approach in recruiting older adults with type 2 diabetes into a 6-month community-based exercise and nutritional supplementation randomised controlled trial (RCT). A secondary aim is to assess the costs associated with the recruitment methods used. METHODS: The Resistance Exercise, Vitamin D and Muscle Protein Intervention Trial (REVAMP-IT) for type 2 diabetes is a 24-week RCT targeting 202 adults with type 2 diabetes which is designed to evaluate whether post-exercise ingestion of a whey- protein and vitamin D-enriched drink can enhance the effects of progressive resistance training (PRT) on glycaemic control, body composition and cardiometabolic health. Participants in this trial were randomly allocated to either: (1) the Lift for Life® community-based PRT program combined with additional whey protein and vitamin D, or (2) the Lift for Life® PRT program alone. Recruitment strategies included state and local newspaper and radio advertisements, targeted mail-outs, doctor and allied health referrals, community presentations, web-based media and word of mouth. The number of expressions of interest, participants screened and included in the trial, and how they first heard about the study were recorded by research staff during the screening process. Reasons for ineligibility or non-participation in the trial were also recorded as was the cost of each recruitment method used. RESULTS: A total of 1157 expressions of interest were received over a 21-month recruitment period. Overall 959 (83 %) individuals were screened and found to be ineligible for the trial or chose not to participate or could not be contacted further following their initial enquiry. As a result, 198 participants were randomised to the 24-week intervention. The most effective recruitment strategies were targeted mass mail-outs (39 % of the total participant sample), state (27 %) and local (14 %) print media. In total recruitment expenditure was AUD$40,421, which equated to AUD$35 per enquiry and AUD$204 per eligible participant. Targeted mail-outs and state print media were the most expensive strategies each accounting for 38 % of total expenditure. CONCLUSIONS: To recruit around 200 older adults with type 2 diabetes into a community-based lifestyle intervention trial in a timely manner, it is important to ensure that an adequate budget is allocated to recruitment as targeted mail-outs and state/local print media were the most costly but effective strategies. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry reference ACTRN12613000592741 . Registered on 27 May 2013.

Consumption of the Soluble Dietary Fibre Complex PolyGlycopleX(®) Reduces Glycaemia and Increases Satiety of a Standard Meal Postprandially.

The effect of consumption of PolyGlycopleX(®) (PGX(®)) was compared to wheat dextrin (WD) in combination with a standard meal, on postprandial satiety and glycaemia in a double-blind, randomised crossover trial, of 14 healthy subjects trained as a satiety panel. At each of six two-hour satiety sessions, subjects consumed one of three different test meals on two separate occasions. The test meals were: a standard meal plus 5 g PGX; a standard meal plus 4.5 g of PGX as softgels; and a standard meal plus 5 g of WD. Subjects recorded fullness using a labelled magnitude scale at 0, 15, 30, 45, 60, 90, and 120 min and the total area under the curve (AUC), mean fullness vs. time was calculated. The meals with PGX (in granular and softgel form) gave higher satiety (AUC) (477 ± 121 and 454 ± 242 cm·min), than the meal with WD (215 ± 261 cm·min) (p < 0.001). Subjects had blood glucose levels measured after the meals with PGX (granules) and WD. Glucose response (AUC) was significantly lower (p < 0.001) after the PGX meal than for the WD meal.  The high viscosity reported for PGX is a likely mechanism behind the significant satiety and blood glucose modulating effects observed in this study.