Thermal treatment can be applied to cereal grains as a pretreatment or processing step in the form of either hydrothermal or dry thermal treatment. These heat treatments result in the occurrence of nonenzymatic browning reactions by means of the Maillard reaction and caramelisation. Nonenzymatic browning is influenced by the type and concentration of sugars and proteins, and the presence of bran. Aside from increasing nonenzymatic browning, thermal treatment increases the antioxidant capacity of cereals and baked goods through the release of bound phenolics. The degree of nonenzymatic browning and antioxidant content in cereal-based products depend on the thermal treatment intensity. Some studies found a decrease in total phenolic content after thermal treatment, due to loss of thermally labile compounds. High-intensity treatment has been shown to produce 5-hydroxymethylfurfural (HMF), furfural, and potentially carcinogenic acrylamide. Acrylamide formation can be mitigated by altering the ingredient composition and the degree of thermal treatment. This review discusses the chemistry of nonenzymatic browning reactions, factors influencing the degree of these reactions, and mitigation strategies for acrylamide. An overview of the effect of dry thermal treatment on nonenzymatic browning and antioxidants in wheat and wheat-based products as well as other cereals is provided. Before concluding with perspectives, a discussion of the relationship between nonenzymatic browning and antioxidant properties is presented. This review of the published literature was conducted using two electronic databases and varying combinations of search terms related to the scope of the review.

ANOVA-simultaneous component analysis (ASCA) was applied to short-wave infrared spectral fingerprints of 5 malting barley varieties collected using a hyperspectral imaging system to determine the effect of germination, the influence of time and the influence of barley by means of a full factorial experimental design. ASCA indicated that there was a significant (p <0.0001) effect of the germination status, the germination time and interaction on the spectral data for all varieties. The biochemical and physiological modification of the samples were characterised by visualisation of the longitudinal scores obtained from simultaneous component analysis for the germination time factor. This resulted in the visualisation and explanation of biochemical change over the course of barley germination as a factor of time. The relevant loadings indicated a significant change to the proteome, lipid and starch structure as driven by the uptake of water over time. The ASCA model were extrapolated to include the effect of barley variety to the already mentioned germination status and germination time factors, resulting once again in all the effects being significant (p < 0.0001). Here it was shown that all the barley varieties are significantly different from one another pre- and post-modification, based on the molecular vibrations observed in the short wave-infrared (SWIR) spectra, suggesting that the detection of biotic stress factors, such as pre-harvest germination, also differ for each variety, by indicating that the germination profile of each barley variety varies as a function of germination time. Thus, also the malting performance, germinative energy and chemical profile of each barley variety tested will vary before, during and after imbibition and germination - indicating the importance of malting commercial barley malt true to variety. These results indicate that (SWIR) spectral imaging instrumentation can possibly be used to monitor controlled germination of barley grain. Due to the shown ability of SWIR spectral imaging to detect small biochemical changes over time of barley grain during germination.

A novel data fusion method based on the use of visible/near-infrared (VNIR) and shortwave infrared (SWIR) imaging sensors, to distinguish between pregerminated and ungerminated barley grain is proposed. Spectral imaging was used to fingerprint germinated and ungerminated barley grain from a total of 5640 average spectra representing single barley kernels varying with respect to germination time. Chemometric approaches utilising partial least squares-discriminant analysis (PLS-DA) and multiblock sequential and orthogonalized partial least squares-linear discriminant analysis (SO-PLS-LDA) and sequential and orthogonalized covariance selection-linear discriminant analysis (SO-CovSel-LDA) were used to build classification models. SO-PLS-LDA achieved a total classification rate of 99.88%, while SO-CovSel-LDA resulted in a classification accuracy of 97.46% when a maximum of 8 variables were selected from each data block (VNIR and SWIR) - models were validated on an independent test set. The use of multiblock approaches led to increased prediction accuracy, compared to PLS-DA, and a viable solution to address the industry problem to detect pregerminated malting barley in a rapid, non-destructive manner. This represents a significant advance with respect to the current dated methods which are hindered by time-consuming wet chemistry techniques and human subjective bias. The potential of the proposed new technique also has the further advantage of moving toward multispectral systems which can be used to detect pre-harvest germinated barley using an even more computationally rapid and affordable online sorting machine incorporating the wavebands of importance selected by SO-CovSel-LDA. The study highlights how sequential and orthogonalised data fusion approaches, in the food and agricultural sector, are powerful solutions to real world problems.

Two commercially available enzymes, Dextrozyme (α-amylase) and Esperase (protease), were covalently immobilized on non-woven electrospun poly(styrene-co-maleic anhydride) nanofiber mats with partial retention of their catalytic activity. Immobilization was achieved for the enzymes on their own as well as in different combinations with an additional enzyme, β-galactosidase, on the same non-woven nanofiber mat. This experiment yielded a universal method for immobilizing different combinations of enzymes with nanofibrous mats containing maleic anhydride (MAnh) residues in the polymer backbone.

Cling films comprise of plasticizers which are known endocrine disrupting chemicals (EDCs). Cling films are commonly used for food packaging and EDCs may leach into food, increasing exposure, leading to adverse health outcomes. We determined the levels of common selected EDCs expected in commercial cling film brands sold in South Africa. We tested for para-nonylphenol (p-NP), bisphenol A (BPA), bis(2-ethylhexyl) adipate (DEHA), and phthalates [di-2-ethyhexyl phthalate (DEHP) and dibutylphthalate (DBP)]. We selected eight brands of cling film and used standard chromatography methods to extract compounds. We found p-NP in one brand (2.06 mu g/kg) and BPA in two brands (1.48 and 1.61 mu g/kg). Five brands contained DEHP (2.1-2.59 mg/kg), DBP (0.62-1.21 mg/kg) and DEHA (165.89-674.07 mg/kg). Levels of DEHA and DEHP in the cling film are associated with potential human health risks. The maximum level of DEHA ranged from 1.6 to 16 times the safe level, with a calculated hazard quotient of 1.4. The two cling film brands made from low density polyethylene (LDPE), both endorsed by the Cancer Association of South Africa (CANSA), had target chemicals below the detection limit.

Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have been detected in drinking water from various countries. Although various water treatment processes can remove EDCs, chemicals can also migrate from pipes that transport water and contaminate drinking water. This study investigated the estrogenic activity in drinking water from various distribution points in Pretoria (City of Tshwane) (n = 40) and Cape Town (n = 40), South Africa, using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay. The samples were collected seasonally over four sampling periods. The samples were also analysed for bisphenol A (BPA), nonylphenol (NP), di(2-ethylhexyl) adipate (DEHA), dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), diisononylphthalate (DINP), 17β-estradiol (E2), estrone (E1) and ethynylestradiol (EE2) using ultra-performance liquid chromatography-tandem mass spectrophotometry (UPLC-MS/MS). This was followed by a scenario based health risk assessment to assess the carcinogenic and toxic human health risks associated with the consumption of distribution point water. None of the water extracts from the distribution points were above the detection limit in the YES bioassay, but the EEq values ranged from 0.002 to 0.114 ng/L using the T47D-KBluc bioassay. BPA, DEHA, DBP, DEHP, DINP E1, E2, and EE2 were detected in distribution point water samples. NP was below the detection limit for all the samples. The estrogenic activity and levels of target chemicals were comparable to the levels found in other countries. Overall the health risk assessment revealed acceptable health and carcinogenic risks associated with the consumption of distribution point water.

The positive effect of lipoxygenase, added as an enzyme-active soy flour, during the production of white bread is well established. In addition to increasing the mixing tolerance and overall dough rheology, lipoxygenase is also an effective bleaching agent. It is known that these effects are mediated by enzyme-coupled cooxidation of gluten proteins and carotenoids. However, the mechanism whereby these effects are achieved is not yet fully understood. In order to gain a better understanding into the reactions governing the beneficial effects of lipoxygenases in bread dough, an in-depth knowledge of the lipoxygenase catalytic mechanism is required. Until now no single review combining the molecular enzymology of lipoxygenase enzymes and their application in the baking industry has been presented. This review, therefore, focuses on the extraction and molecular characterization of lipoxygenases in addition to the work done on the application of lipoxygenases in the baking industry.