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Annealing offers a facile and green approach to the modification of starch. This study was the first to investigate the effect of annealing on the properties of waxy rice starch nanoparticles (SNPs). The spherical morphology of SNPs hardly changed after annealing, and the nanoscale size of the SNPs was maintained in the range of 50–120 nm. The relative crystallinity of modified SNPs increased from 53.71% to 63.46% after annealing at 55 °C for 48 h. The annealing treatment increased the melting temperature from 78.3 °C to 95.7 °C, but decreased the melting range from 30.8 °C to 25.3 °C. The increased 1047 cm−1:1022 cm−1 ratio suggested that annealing resulted in an efficient packing of double helices. This work suggests that annealing, a safe and green method, produces modifications which can improve the properties of SNPs and therefore expand their applications in the fields of food, nutraceuticals, and other materials.

The co-melting behaviour of sugar mixtures, comprising sucrose, glucose and fructose at various binary (3:1, 1:1, 1:3, 1:7, 1:15) and ternary (4:1:1, 2:1:1, 1:1:1, 2:5:5, 2:11:11, 1:4:1, 1:10:1) ratios, was studied using DSC. The melting temperature of sucrose was found to decrease in the presence of either fructose or glucose. In the sugar mixtures, the melting enthalpy of sucrose decreased compared with the proportional calculated values, using the percentage equation, whilst the melting enthalpy of fructose or glucose increased at the same time, implying the melting or dissolution of sucrose together with fructose or glucose. The tested enthalpy is usually higher than the calculated enthalpy for fructose, but lower than the calculated enthalpy for sucrose. Microscopic pictures showed that sucrose crystals could melt and dissolve gradually in the fructose melt liquid. This study provides useful information for both fundamental understanding of sugars co-melting and food industry applications.

Adulteration of the high-value silver pomfret (Pampus argenteus) is a serious problem worldwide, necessitating accurate identification and quantification of the species. In this study, optimisation of the digital droplet PCR (ddPCR) assay for the identification and quantification of the silver pomfret was carried out. The primer and probe concentrations, melting temperature, and PCR cycle number were optimised by combining single-factor experiments with an orthogonal experimental design. The absolute limits of detection and quantification of the ddPCR were 2copies/μl and 21 copies/μl, respectively. Its sensitivity was 0.1% for meat mixtures and 0.5% for DNA mixtures. The ddPCR was 156 times more sensitive than the real-time PCR, although both methods had similar specificities. However, the overall time needed to complete the ddPCR method was twice that of the real-time PCR. Notwithstanding, the ddPCR methodology established in this study can be a valuable tool for addressing species adulteration issues.

SDRT-PCR (SYBR duplex real-time polymerase chain reaction) was designed for an assay that can combine the advantages of real-time PCR and multiplex PCR to identify animal genes more quickly. SDRT-PCR based on melting temperature (tm) discrimination by using SYBR Green fluorescence dye was developed for the analysis of ruminant and poultry contained in foodstuffs. Primers specific to ruminant and poultry were designed for species-specific gene-amplification. Appropriate mixtures of poultry and ruminant meat DNAs were used to develop the assay. Gene products of ruminant and poultry were represented in two melting peaks generated simultaneously at temperatures of 83.2 and 86.5 °C, respectively. Duplexing results obtained with one of the multiplex polymerase mixes correlated extremely well with the singleplex reference. The objective of the study was to design a rapid, specific and accurate duplex real-time PCR assay by using SYBR Green fluorescence dye that is cheaper than double labelled probes to detect a group of mixed meats simultaneously.

The crystalline, thermal and textural properties of chestnut starches (CSs I–V) at 0%, 25%, 50%, 75% and 100% degrees of hardening (DHs) were investigated in this work. CS I had a structure of C-type crystallinity. With the increase of DH, more B-type crystalline regions and amylose–lipid complexes were formed. The gelatinisation temperature of CS and melting temperature of amylose–lipid complexes were not significantly changed as DH increased. However, a significant (P

Gelatins were prepared from the skins of the tropical fish, sin croaker ( Johnius dussumeiri ) and shortfin scad ( Decapterus macrosoma ). Visual appearance, colour, pH, bloom strength, viscoelasticity, melting point and amino acid profiles of the fish gelatins were evaluated. Shortfin scad gelatin had higher melting and gelling temperatures than those of sin croaker gelatin. The bloom strengths of gelatins from sin croaker and from shortfin scad were 125 and 177 g, respectively, compared to 240 g for commercial bovine gelatin. The pH values were significantly different between the solutions of the two fish gelatins. The elastic modulus ( G ′) of the fish gelatin gels increased by more than 10-fold and the viscous modulus ( G ″) of fish gelatin solution increased sixfold after holding at 5 °C for 2 h. These viscoelastic properties of bovine gelatin only increased by less than twice.

The effects of repeated retrogradation (RR) treatment on the structural characteristics and in vitro digestibility of waxy potato starch were investigated. The cycling times of RR ranging from 1 to 5 were designated as RR-1, RR-2, RR-3, RR-4, and RR-5, respectively. A maximum SDS content (40.41%) was obtained by RR-2 treatment with the time interval of 48h. RR-2-treated starch product exhibited a narrower melting temperature range, a higher onset temperature and a lower melting enthalpy compared with RR-1 treatment. Compared with native starch, X-ray diffraction patterns of treated starches were altered from B-type to C-type. The variation in relative crystallinity of RR-treated starch products was consistent with that in melting enthalpy. Moreover, compared with RR-1-treated starch, a large number of cavities were observed on the surface of RR-2-treated starch product with a time interval of 48h, whereas more smooth regions were found on the surface of RR-5-treated starch product. This study suggested that structural changes of waxy potato starch treated with different cycling times of RR significantly affected the digestibility.

In order to understand the effect of pre-dehydration on the in vitro digestibility of cookie starch, cookie dough samples were dehydrated by vacuum treatment, and melting temperature (T(m)) of the crystalline amylopectin in the dough, internal temperature and water content of the dough during baking, and non-hydrolysed starch content of the obtained cookies were investigated. The T(m) of crystalline amylopectin increased with decreased water content of the dough, and the result was described as a T(m)-curve. The internal temperature of non-dehydrated dough surpassed the T(m)-curve during baking. Pre-dehydrated dough, on the other hand, always indicated a lower internal temperature than the T(m)-curve. The non-hydrolysed starch content obtained under a given condition increased significantly with a decrease in the initial water content of cookies. This will be because the melting of crystalline amylopectin was prevented, at least partially, during baking.