7 research outputs found
Vis-NIR Hyperspectral Imaging for Online Quality Evaluation during Food Processing: A Case Study of Hot Air Drying of Purple-Speckled Cocoyam (Colocasia esculenta (L.) Schott)
In this study, hyperspectral imaging (HSI) and chemometrics were implemented to develop prediction models for moisture, colour, chemical and structural attributes of purple-speckled cocoyam slices subjected to hot-air drying. Since HSI systems are costly and computationally demanding, the selection of a narrow band of wavelengths can enable the utilisation of simpler multispectral systems. In this study, 19 optimal wavelengths in the spectral range 400–1700 nm were selected using PLS-BETA and PLS-VIP feature selection methods. Prediction models for the studied quality attributes were developed from the 19 wavelengths. Excellent prediction performance (RMSEP 0.90, RPDP > 3.5) was obtained for MC, RR, VS and aw. Good prediction performance (RMSEP 2.0) was obtained for PC, BI, CIELAB b*, chroma, TFC, TAA and hue angle. Additionally, PPA and WI were also predicted successfully. An assessment of the agreement between predictions from the non-invasive hyperspectral imaging technique and experimental results from the routine laboratory methods established the potential of the HSI technique to replace or be used interchangeably with laboratory measurements. Additionally, a comparison of full-spectrum model results and the reduced models demonstrated the potential replacement of HSI with simpler imaging systems.Peer Reviewe
Influence of blend proportion and baking conditions on the quality attributes of wheat, orange‑fleshed sweet potato and pumpkin composite flour dough and bread: optimization of processing factors
Gefördert durch den Publikationsfonds der Universität Kasse
Malokklusionen und klinische Zeichen sowie subjektive Symptome kraniomandibul�rer Dysfunktionen bei Erwachsenen
Comparison between Hyperspectral Imaging and Chemical Analysis of Polyphenol Oxidase Activity on Fresh-Cut Apple Slices
The assessment of the quality of fresh-cut apple slices is important for processing, storage, market value, and consumption. Determination of polyphenol oxidase activity (PPO) in apples is critical for controlling the quality of the final product (i.e., dried apples and juices). Hyperspectral imaging (HSI) is a nondestructive, noncontact, and rapid food quality assessment technique. It has the potential to detect physical and chemical quality attributes of foods such as PPO of apple. The aim of this study was to investigate the suitability of HSI in the visible and near-infrared (VIS-NIR) range for indirect assessment of PPO activity of fresh-cut apple slices. Apple slices of two cultivars (cv. Golden Delicious and Elstar) were used to build a robust detection algorithm, which is independent of cultivars and applied treatments. Partial least squares (PLS) regression using the 7-fold cross-validation method and method comparison analysis (Bland–Altman plot, Passing–Bablok regression, and Deming regression) were performed. The 95% confidence interval (CI) bands for the Bland–Altman analysis between the methods were −4.19 and 13.11, and the mean difference was 3.7e−12. The Passing–Bablok regression had a slope of 0.8 and an intercept of 7.6. The slope of the Deming regression was 0.8 within the CI bands of 0.56 and 1.10. These results show acceptable performance and no significant deviation from linearity. Hence, the results demonstrated the feasibility of HSI as an indirect alternative to the standard chemical analysis of PPO enzyme activity
Influence of Brewer’s Spent Grain Compounds on Glucose Metabolism Enzymes
With a yearly production of about 39 million tons, brewer’s spent grain (BSG) is the
most abundant brewing industry byproduct. Because it is rich in fiber and protein, it is commonly
used as cattle feed but could also be used within the human diet. Additionally, it contains many
bioactive substances such as hydroxycinnamic acids that are known to be antioxidants and potent
inhibitors of enzymes of glucose metabolism. Therefore, our study aim was to prepare different
extracts—A1-A7 (solid-liquid extraction with 60% acetone); HE1-HE6 (alkaline hydrolysis followed
by ethyl acetate extraction) and HA1-HA3 (60% acetone extraction of alkaline residue)—from various
BSGs which were characterized for their total phenolic (TPC) and total flavonoid (TFC) contents,
before conducting in vitro studies on their effects on the glucose metabolism enzymes α-amylase,
α-glucosidase, dipeptidyl peptidase IV (DPP IV), and glycogen phosphorylase α (GPα). Depending
on the extraction procedures, TPCs ranged from 20–350 μg gallic acid equivalents/mg extract
and TFCs were as high as 94 μg catechin equivalents/mg extract. Strong inhibition of glucose
metabolism enzymes was also observed: the IC50 values for α-glucosidase inhibition ranged from
67.4 ± 8.1 μg/mL to 268.1 ± 29.4 μg/mL, for DPP IV inhibition they ranged from 290.6 ± 97.4 to
778.4 ± 95.5 μg/mL and for GPα enzyme inhibition from 12.6 ± 1.1 to 261 ± 6 μg/mL. However, the
extracts did not strongly inhibit α-amylase. In general, the A extracts from solid-liquid extraction
with 60% acetone showed stronger inhibitory potential towards α-glucosidase and GPα than other
extracts whereby no correlation with TPC or TFC were observed. Additionally, DPP IV was mainly
inhibited by HE extracts but the effect was not of biological relevance. Our results show that BSG
is a potent source of α-glucosidase and GPα inhibitors, but further research is needed to identify
these bioactive compounds within BSG extracts focusing on extracts from solid-liquid extraction
with 60% acetone
Influence of Brewer’s Spent Grain Compounds on Glucose Metabolism Enzymes
With a yearly production of about 39 million tons, brewer’s spent grain (BSG) is the
most abundant brewing industry byproduct. Because it is rich in fiber and protein, it is commonly
used as cattle feed but could also be used within the human diet. Additionally, it contains many
bioactive substances such as hydroxycinnamic acids that are known to be antioxidants and potent
inhibitors of enzymes of glucose metabolism. Therefore, our study aim was to prepare different
extracts—A1-A7 (solid-liquid extraction with 60% acetone); HE1-HE6 (alkaline hydrolysis followed
by ethyl acetate extraction) and HA1-HA3 (60% acetone extraction of alkaline residue)—from various
BSGs which were characterized for their total phenolic (TPC) and total flavonoid (TFC) contents,
before conducting in vitro studies on their effects on the glucose metabolism enzymes α-amylase,
α-glucosidase, dipeptidyl peptidase IV (DPP IV), and glycogen phosphorylase α (GPα). Depending
on the extraction procedures, TPCs ranged from 20–350 μg gallic acid equivalents/mg extract
and TFCs were as high as 94 μg catechin equivalents/mg extract. Strong inhibition of glucose
metabolism enzymes was also observed: the IC50 values for α-glucosidase inhibition ranged from
67.4 ± 8.1 μg/mL to 268.1 ± 29.4 μg/mL, for DPP IV inhibition they ranged from 290.6 ± 97.4 to
778.4 ± 95.5 μg/mL and for GPα enzyme inhibition from 12.6 ± 1.1 to 261 ± 6 μg/mL. However, the
extracts did not strongly inhibit α-amylase. In general, the A extracts from solid-liquid extraction
with 60% acetone showed stronger inhibitory potential towards α-glucosidase and GPα than other
extracts whereby no correlation with TPC or TFC were observed. Additionally, DPP IV was mainly
inhibited by HE extracts but the effect was not of biological relevance. Our results show that BSG
is a potent source of α-glucosidase and GPα inhibitors, but further research is needed to identify
these bioactive compounds within BSG extracts focusing on extracts from solid-liquid extraction
with 60% acetone