The protective effect of cyclodextrin on the color quality and stability of Cabernet Sauvignon red wine

The impact of cyclodextrins(CDs)on wine quality and stability remains largely unknown.This study systematically assessed the protective effect of the post-fermentation addition of CDs on color stability of red wine from the viewpoints of color characteristics,copigmentation and phenolic profiles.The grey relational analysis(GRA)and principal component analysis(PCA)methods were employed to dissect the key effective determinants related to color quality.The addition of CDs induced a significant hyperchromic effect of 8.19-25.40%,a significant bathochromic effect and an enhancement of the color intensity.Furthermore,the evolution of anthocyanin forms and the content of monomeric anthocyanins revealed that β-CD is a superior favorable cofactor during wine aging,but for long-term aging,2-HP-β-CD and 2-HP-γ-CD are more beneficial in promoting the formation of polymerized anthocyanins and color stability.This work provides an important reference for the use of CDs to enhance the color quality and stability of red wines.

Effect of Secondary Sterilization on the Quality of Roasted Whiteleg Shrimp(Litopenaeus vannamei)

This study was carried out to investigate the effects of secondary sterilization on the quality of roasted shrimp（ Litopenaeus vannamei）with high nutrients. Roasted shrimps were vacuum packaged, with 100 g in each bag, and subjected to secondary sterilization for 30 min at 70, 80,90, 100, 110 and 120 ℃, or for 10, 20, 30, 40 and 50 min at 90℃. Then, the color, textural properties, sensory quality and pH were measured, and whether they were commercially sterile was evaluated. The results showed that with the increase of sterilizing temperature, L＊, a＊and b＊values all decreased. And with the increase of the duration of sterilization, L＊slightly decreased, while a＊and b＊slightly increased. In addition, with the increase in sterilizing temperature, the hardness, gumminess, chewiness and springiness of roasted shrimps increased at first and decreased subsequently, while the adhesiveness kept increasing, and the cohesiveness and shear force slightly declined. With the increasing duration of sterilization,the hardness, adhesiveness and chewiness rose, the cohesiveness and shear force declined, the gumminess decreased at first and increased subsequently, while the springiness increased at first and decreased subsequently. The pH of roasted shrimps varied in a complex pattern when sterilizing temperature was increased, but increased with the increasing duration of sterilization. The results showed that the roasted shrimps secondarily sterilized at 90℃ for 30 min have the best sensory quality, and are commercially sterile.

Synthesis of γ-Ce_2S_3 colorant under low temperature and its coloring properties for PE and PVC

A series of cerium sulfides were successfully prepared using commercially available nanoscale CeO_2 as precursor, anhydrous Na_2CO_3 as dopants, CS_2 as sulfur source, under 600–800 oC, respectively. Properties of samples were investigated by means of X-ray diffraction（XRD）, scanning electron microscopy（SEM） and spectrophotometry. The results showed that corresponding γ-Ce_2S_3 with small size was obtained by using nanoscale CeO_2 as precursor; pure phase γ-Ce_2S_3 could be obtained under low temperature of 700 oC. Coloring properties of γ-Ce_2S_3 obtained under 800 oC were studied by researching γ-Ce_2S_3/PE and γ-Ce_2S_3/PVC composites, respectively. The results showed that satisfied coloring effects to PE and PVC were obtained by using 0.5 phr and 0.2 phr γ-Ce_2S_3, respectively.