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The retrogradation behaviors and molecular structures of lotus seed starch (LS) combined with different hydrocolloids, chitosan (CS), guar gum (GG) and xanthan (XN), were investigated. Following an autoclave treatment, the storage modulus (G') value of LS-CS increased more rapidly than LS alone, indicating an increase in starch retrogradation. This might result from intermolecular interactions, increased ordered structure, decreased weight-average molecular weight (Mw) and greater leached amylose content in LS-CS system. The LS-GG and particularly LS-XN blends showed the opposite trend. The much greater Mw of LS-XN was mainly attributed to the lower retrogradation rate. The enwrapping effect of GG or XN on LS, as observed by confocal laser scanning microscopy, might retard their retrogradation by limiting the granules' swelling and the amylose leaching. Overall, the changes in the interaction force, ordered structure, Mw, leached amylose and microstructure were related to retrogradation behaviors of LS-hydrocolloid blends following an autoclave treatment.

This study aimed to determine how the cooking methods change the phenolics and saponins profiles, oligosaccharides, antinutrients and antioxidant properties of flours from colorful beans. The autoclave cooking consisted of: 6 h soaking and 5 min cooking (C5); and 20 min cooking without soaking (C20). Both cooking methods significantly promote changes on the chemical compounds studied, and the intensity of these variations were affected by the cultivars. Most of flours of C5 beans presented a lower loss of anthocyanins (3.9–70.0%), DPPH (11.7–87.2%), ABTS (0.0–82.7%), and tannins (0.0–90.0%) compared with C20. The cooked flours of Artico and Realce showed some similarities among chemical compounds, as well as the lowest concentration of tannins (0.0 mg‧g−1), antioxidant activity (0.40 µmol Trolox‧g−1), and higher amounts of oligosaccharides and acetylcholine. Most of cooked flours presented a reduction in phenolics and soyasaponins αg and βg, and an increase in soyasaponins Ba and I and oligosaccharides (mainly C20 flours).

The present study aimed to investigate the physical and turbidimetric properties of cholecalciferol- and menaquinone-loaded lipid nanocarriers emulsified with different ratios of polysorbate 80 and soy lecithin. The lipid nanocarriers were subjected to three different heat treatments, LTLT (low temperature long time), HTST (high temperature short time), and autoclave treatments. Both cholecalciferol and menaquinone were successfully encapsulated in lipid nanocarriers and there was little loss of them during preparation. The droplet size of lipid nanocarriers emulsified with only polysorbate 80 increased and its PDI became larger than 0.3 after autoclave treatment. Moreover, 30.9% and 49.4% of cholecalciferol and menaquinone, respectively, were lost. In turbidimetric analysis, the destabilization by creaming formation in the upper layer of the lipid nanocarriers emulsified with a high polysorbate ratio was observed. However, the use of combination of both emulsifiers inhibited destabilization by flocculation as well as retained the cholecalciferol and menaquinone after all heat treatments.

Heat stabilization of wheat bran aims at inactivation of enzymes which may cause rancidity and processability issues. Such treatments may however cause additional unanticipated phenomena which may affect wheat bran technological properties. In this work, the impact of toasting on wheat bran hydration capacity and hydration kinetics was studied. Hydration properties were assessed using the Enslin-Neff and drainage centrifugation water retention capacity methods, thermogravimetric analysis and contact angle goniometry, next to more traditional methods. While equilibrium hydration properties of bran were not affected by the heat treatment, the rate at which the heat treated bran hydrated was, however, very significantly reduced compared to the untreated bran. This phenomenon was found to originate from the formation of a lipid coating during the treatment rendering the bran surface hydrophobic. These insights help to understand and partially account for the modified processability of heat treated bran in food applications.

The effects of chemical, physical, and cooking treatments on the reduction of aflatoxin B1 (AFB1), B2, G1, and G2 in soybean matrix were investigated. A HPLC-FLD with a Kobra cell system was used for the quantitative analysis of aflatoxins (AFs). To decrease the level of AFs during the soaking process, the contaminated soybeans were submerged in organic acid solutions. The reduction rates of AFB1 in 1.0 N citric acid, lactic acid, succinic acid, and tartaric acid for 18 h were 94.1%, 92.7%, 62.0%, and 95.1%, respectively. In the case of pH and autoclave treatment, the level of AFB1 was significantly decreased during autoclaving process at pH 7.4, 9.0, and 11.1, compared with the non-autoclaved samples (p

Autoclave cooking is used to produce "convenience" rice. In this study, autoclaving effects on sensory properties are investigated, and mechanistic explanations in terms of the underlying molecular structure are explored by analyzing this structure by size-exclusion chromatography and fitting the results with models based on biosynthetic processes. Compared to steam cooking, autoclaving produces stickier texture, and slightly affects hardness. It is found that molecular sizes of leached starch of both autoclaved and steam cooked rice are similar, but significantly smaller than that of the parent grain starch; model fitting parameters of leached amylopectin and amylose structures between autoclaved rice and steam cooked rice display no large variations. The amount of leached amylopectin (an important texture-controlling parameter) of autoclaved rice is higher than that of steam cooked rice. Correlation analysis indicates that, compared to steam-cooked rice, the stickier texture of autoclaved rice is caused by more amylopectin leaching during autoclaving.

The effects of autoclave and microwave heating on the protein and oil in soybean seeds were investigated under low moisture conditions. The nitrogen solubility index (NSI) decreased on heating. The reduction in the NSI was accompanied by an increase in the size and deformation of the oil bodies in the cellular tissue of soybean seeds. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that lipoxygenase was susceptible to heat denaturation, but 7S and 11S globulins were only partially denatured. The partial denaturation of the proteins was confirmed by Fourier transform infrared spectroscopy measurements. The ratio of oil to protein peaks increased with increasing heating, suggesting the exudation of oil to the surface or outside of oil bodies. Microwave heating is more efficient in changing the oil distribution in soybean seeds than autoclave heating. On the other hand, the degree of protein denaturation is lower after microwave heating.

Nisin is applied broadly in the food industry as an antimicrobial peptide. The objective of this study is to prepare nisin nanoparticles using free nisin by a facile nanoprecipitation technique and to investigate their antimicrobial activity after high-temperature processing. Transmission electron microscopic images showed that the size of extra-small nisin nanoparticles with different initial concentrations of nisin (0.1%, 0.3% and 0.5%) was 5, 10 and 15 nm, respectively. The nisin nanoparticles were stable at pH 5.0 with the smallest size. Moreover, nisin nanoparticles exhibited a higher antimicrobial activity than free nisin at a concentration below 2.0 mg/ml after autoclave treatment. These results suggested that nisin nanoparticles could serve as a potential food preservative.

Formulations of tomato puree with grape skin fibres (Chardonnay variety) having varying particle sizes were studied. The contents of flavonoids (by HPLC–DAD) and proanthocyanidins ( n -butanol/HCl assay), reducing capacity (ferric ion reducing antioxidant power, FRAP) and anti-glycation activity by a bovine serum albumin (BSA)/fructose model system were analysed in vitro . A liking test was performed with consumers. Stabilization was carried out by either an intensive autoclave treatment or an optimised microwave-treatment achieving 6D-reduction of the target microorganism ( Alicylobacillus acidoterrestris ). In the fortified tomato purees, the solubility of proanthocyanidins decreased, but was partly restored by autoclave treatment, which also caused deglycosylation of flavonol glycosides. Microwave treatment did not show any effect on phenolics. The reducing capacity and ability to inhibit protein glycation greatly increased in the fortified purees. The particle sizes of solids in the formulations played a major role with respect to the consumers’ liking, with the smallest fraction showing maximum ratings.

The contents of Pb and Cd in two species of Iranian tuna fish (yellowfin and skipjack), which were caught from the Persian Gulf and Oman Sea, and the effects of canning processing steps on their contents were assessed by electrothermal atomic absorption spectrometry. The results revealed that the levels of lead and cadmium throughout the processing steps in yellowfin were in range of 0.154 ± 0.019–0.441 ± 0.025 μg/g and 0.029 ± 0.002–0.084 ± 0.0005 μg/g, respectively. Pb and Cd concentrations from received fish to final product in skipjack were found to be in range of 0.072 ± 0.031–0.218 ± 0.031 μg/g and 0.016 ± 0.001–0.062 ± 0.002 μg/g, respectively. The limit of detection for lead and cadmium were 0.058 μg/g (11.6022 μg/l) and 0.0007 μg/g (0.1485 μg/l), respectively. Results from paired sample t-test analysis showed that defrosting, cooking, and sterilisation by autoclave would reduce the contents of lead and cadmium, considerably.

This study was carried out to investigate changes in the free amino acid contents and antioxidant activity of Panax ginseng induced by steaming at different temperatures. For this purpose, white ginseng (WG), red ginseng (RG, ginseng steamed at 100 °C) and ginseng steamed at 120 °C (SG) were prepared using an autoclave. Most free amino acids were decreased significantly by steam treatment, with the greatest reduction observed in SG. Total content of free amino acids, 17.9 mg/g in WG was reduced to 12.2 mg/g in RG and 2.79 mg/g in SG. As for Arg which is the most predominant amino acid in ginseng, the content, 10.4 mg/g in WG, decreased significantly to 1.38 mg/g in SG. In particular, β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), a well-known neurotoxin, was reduced by 92.9% in SG. In contrast, the level of Maillard reaction products (MRPs) increased with steam treatment, which indicates that the reduction of most amino acids is attributed to the extent of the Maillard reaction. Based on MRPs being useful antioxidants, we assayed the scavenging activity against free radicals produced by 2,2′-azobis-(2-amidinopropane) dihydrochloride (AAPH). The radical scavenging activity of a ginseng extract increased with steam treatment, with the most potent activity in SG. Further, MRPs-rich fraction in SG showed powerful antioxidant activity, which indicates MRPs are major contributors to antioxidant activity enhanced by steam treatment.

Mushroom lectins have been reported as immunomodulatory proteins. To evaluate their functionalities, as affected by various industrial procedures, two mushroom proteins, including Agaricus bisporus lectin (ABL) and the immunomodulatory protein of Auricularia polytricha (APP), were treated by various methods, mimicking food processing procedures, in prior-to-cell experiments, and their macrophage-activating functionalities were determined in the induction of tumor necrosis factor-alpha (TNF-α) and nitric oxide (NO) productions by RAW264.7 cells in vitro . The remaining activities of ABL and APP, after autoclave treatment (121 °C, 15 min), were observed to be 77.4% and 80.7%, respectively, in their stimulations of TNF-α production by cells. Boiling (100 °C, 30 min) and freezing (−80 °C, 24 h) treatments did not reduce their effects on TNF-α and NO secretions, while treating with pH 2 and pH 13 buffers only resulted in insignificant decrease of the ABL- and APP-induced TNF-α and NO production. Moreover, ABL and APP also withstood vacuum dehydration with 96.5% and 84.6% of activities being retained, respectively, in their stimulations of TNF-α production. These findings revealed that ABL and APP had thermal/freezing-resistant, acid/alkali tolerance and dehydration stable properties, and that they were potential candidates, as stable immune stimulants, for health food and pharmaceutical utilization.

The effect of heat treatment on the changes in the overall antioxidant activity and polyphenolic compounds of Shiitake extract was investigated. Raw Shiitake was heated at 100 and 121 °C for 15 or 30 min using an autoclave. After heat treatment, the free and bound polyphenolics and flavonoids in the mushroom extracts were analyzed. 2,2-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were measured to evaluate antioxidant activity of the extracts. The polyphenolic contents and antioxidant activities in the extracts increased as heating temperature and time increased. For example, the free polyphenolic content in the extract heated at 121 °C for 30 min was increased by 1.9-fold compared to that in the extract from the raw sample. The ABTS and DPPH radical scavenging activities were increased by 2.0-fold and 2.2-fold compared to the raw sample, respectively. There was a good correlation between total polyphenolic contents and AEAC ( p

Factors influencing the formation of resistant starch (RS) during gelatinization and retrogradation were studied in starches and flours from cereals (wheat, corn, rice) and potato. RS obtained using a high-pressure autoclave system varied between 3.94 and 21.21% (rice and potato starches, respectively) similar to the values obtained after gelatinization in a boiling water bath. Except for rice, RS was higher in pure starches than in flours. Stirring during gelatinization yielded more homogeneous products than non-stirred samples. Apparently, gelatinization was unaffected by pH values between 3.5 and 10.5. To obtain optimum RS yields during retrogradation, it was necessary to cool down starch gels prior to freezing, followed by thawing at room temperature and drying at 60°C. These conditions ensure good yields in the formation of RS with potential industrial applications. ©

Egyptian and Italian varieties of chick pea were analysed chemically to study their total constituents. The two varieties were cooked for 1 and 2 h and autoclaved for 1 h at 121°C. Their constituent basic amino acids, tryptophan, thiamin, pyridoxin and niacin, were determined. There were differences in the chemical constituents between the two varieties. Cooking decreased lysine, histidine and arginine, the effect being highly significant. Tryptophan decreased, the effect being significant. In addition, protein solubility decreased with increased cooking time. The vitamin content also decreased with increased cooking time. It is preferable to cook chick pea in an autoclave at 121°C for not more than 1 h to minimise losses in vitamins and amino acids.