Hypotriglyceridemic and hypoglycemic effects of vescalagin from Pink wax apple [Syzygium samarangense (Blume) Merrill and Perry cv. Pink] in high-fructose diet-induced diabetic rats

Vescalagin, an active component from Pink wax apple [Syzygium samarangense (Blume) Merrill and Perry cv. Pink] fruit, with glucose uptake enhancing ability in insulin-resistant FL83B mouse hepatocytes, as shown in our previous study, was further evaluated for its hypotriglyceridemic and hypoglycemic effects in high-fructose diet (HFD)-induced diabetic rats. Wistar rats were fed HFD for 16 weeks and orally administered with vescalagin from Pink wax apple daily during the last 4 weeks. The results of biochemical parameters showed that fasting blood glucose, C-peptide, fructosamine, triglyceride and free fatty acid contents decreased by 44.7%, 46.2%, 4.0%, 42.5%, and 10.8%, respectively, in the HFD-induced diabetic rats administered with vescalagin at 30 mg/kg body weight in comparison with those of control HFD-induced diabetic rats. However, high-density-lipoprotein-cholesterol content increased by 14.4% in the HFD rats treated with vescalagin. The present study reveals that vescalagin could have therapeutic value against diabetic progression via its anti-hypertriglyceridemic and anti-hyperglycemic effects.     

HPLC法同时测定采后莲雾果实7种有机酸的含量

为探讨采后莲雾果实有机酸代谢对果实絮状绵软和品质的影响,建立同时测定莲雾果实中7种有机酸含量的高效液相色谱法.采用Atlanis T3色谱柱(4.6 mm×250 mm,5μm)分离并进行梯度洗脱,流动相为甲醇和0.02 mol/L的磷酸盐(pH 2.2),流速0.5 mL/min,柱温25℃,紫外检测器,检测波长21...     

Physicochemical changes of tilapia (Oreochromis niloticus) muscle during salting

The effect of wet and dry saltings on the physicochemical changes of tilapia (Oreochromis niloticus) muscle was investigated. Dry salting resulted in the higher rate of salt uptake into tilapia muscle facilitating the faster decrease in A_w (p < 0.05). The pH of both dry and wet salted fish muscles tended to decrease throughout the salting time and the lower pH was found in dry salted fish (p < 0.05). The increase in the protein content in the salting medium was found during wet salted tilapia production (p < 0.05). The TCA-soluble peptide content tended to decrease with increasing the salting time in both salting methods (p < 0.05), suggesting a leaching effect of the salting medium or the exudative loss occurred in salted tilapia. Wet salting caused the greater formation of metmyoglobin in tilapia muscle when compared to dry salting at all time points (p < 0.05) and the content of metmyoglobin increased as salting time increased in both salting methods (p < 0.05). A lowered metmyoglobin with a lowered redness index of dry salted tilapia muscle was found, indicating the continuous oxidation of metmyoglobin to other hypervalent derivatives and hence the discolouration of salted tilapia. Lipid hydrolysis and oxidation of tilapia meat occurred with varying degrees in both salting methods and these changes depended on salting time. Dry salting resulted in a higher oxidation of tilapia muscle lipid as indicated by the higher PV and TBARS throughout the salting period when compared with that of wet salting (p < 0.05). In conclusion, the physicochemical changes of tilapia muscle during salting are governed by the salting method and the salting time applied.     

Physicochemical and functional changes in jumbo squid (Dosidicus gigas) mantle muscle during ice storage

Physicochemical and functional changes of jumbo squid (Dosidicus gigas) mantle muscle stored in ice for 15 days were evaluated. Proximate analysis, pH, protein solubility (PS) and SDS-PAGE profile changes were monitored for muscle proteins, while texture profile analysis (TPA) (gel strength, elasticity and cohesiveness), water holding capacity (WHC) and colour changes were monitored for gels produced from this muscle. Fresh muscle chemical composition varied according to fishing season and/or physiological status presented by specimens. pH and PS were stable (p ? 0.05) throughout the study with a slight tendency to decrease towards the end of study. SDS-PAGE revealed no drastic changes in proteins influencing gelation (i.e., myosin). TPA and WHC of gels decreased towards the end of experiment; however, due to sampling variability, no significant differences (p ? 0.05) were found over storage time. Changes in gel colour were observed with hue angle decreasing towards yellow hues. Improved post-capture management of mantle muscle preserved its integrity and functionality for up to two weeks.     

Phytochemical changes in fresh-cut jackfruit (Artocarpus heterophyllus L.) bulbs during modified atmosphere storage

A minimal process was carried out for pitted jackfruit (Artocarpus heterophyllus L.) bulbs using additives CaCl₂, ascorbic acid (AA), and sodium benzoate in combination with mild acidified conditions for storage under modified atmosphere (MA), i.e., 3 kPa O₂ + 5 kPa CO₂, gas mixture flushed polyethylene (GFPE) bags, polyethylene terephthalate jars with silicon membrane on lid and polyethylene bag with air. Samples devoid of any additive based pretreatment but packaged in similar MA conditions were used as experimental control. A restricted loss of around 7%, 8%, 43%, and 31% was found for total phenolics (TP), total flavonoids (TF), total carotenoids (TC), and AA contents respectively in the pretreated samples kept under GFPE bags towards the end of 35 days storage at 6 °C. Among the phytochemicals evaluated, the radical-scavenging activity showed the highest correlation (r = 0.979) with AA followed by TP, TF and TC.     

Pink discoloration and quality changes of squid (Loligo formosana) during iced storage

Pink discoloration and quality changes of squid (6-10 squids/kg) with and without deskinning during iced storage at different squid/ice ratios (1:1 and 1:2, w/w) for 16 days were investigated. The increases in a* and b*-values of squid mantle were observed with increasing storage time (p < 0.05), indicating the formation of pink color on the mantle. The increase was more pronounced in squid without deskinning with a squid/ice ratio of 1:1 (p < 0.05). No changes in a*-value were observed in deskinned squid throughout the storage, regardless of squid/ice ratio (p > 0.05). However, the slight increase in b*-value was found in the squid with deskinning during the storage. Psychrophilic bacteria counts of squid increased continuously as the storage time increased. Coincidental increases in total volatile base (TVB), trimethylamine (TMA) and ammonia contents were observed during the storage. The rates of increase were greater in the samples with a squid/ice ratio of 1:1 than those found in the samples kept in ice with a squid/ice ratio of 1:2. Pink discoloration, psychrophilic bacteria count, TVB and TMA contents were much lowered when the squid without deskinning was treated with 0.1 g/100 mL sodium azide (NaN₃) prior to storage, suggesting that microbial growth was associated with those changes. Therefore, deskinning together with icing using a sufficient amount of ice as well as the use of safe antimicrobial agent could be a means to lower the pink discoloration and retard the losses in quality of squid stored in ice.     

鳙鱼鱼糜在冻藏过程中理化性质变化的研究

研究了不同温度冻藏条件下鳙鱼(Aristichthysnobilis)鱼糜的品质变化。鳙鱼鱼糜分别冻藏于-10℃、-20℃和-30℃条件下,冻藏过程中肌原纤维蛋白质Ca2 -ATPase活性和总-SH含量不断下降,冻藏20周后分别下降至新鲜样品的16.9%、64.1%、77.4%和53.1%、60.2%、66.1%,凝胶强度也呈现下降趋势,同Ca2 -ATPase活性和总-SH含量变化相一致。鱼糜微结构表明,不同温度冻藏条件下,鱼肉蛋白质中冰结晶大小有很大差异,冰晶的影响是导致蛋白质变性的主要原因。     

Physicochemical changes in ω − 3-enhanced farmed rainbow trout (Oncorhynchus mykiss) muscle during refrigerated storage

Physicochemical changes of ω − 3-enhanced farmed rainbow trout (Oncorhynchus mykiss) fillets developed by dietary modification with flaxseed oil and α-tocopheryl acetate (α-TA) were determined during storage at 2 °C. Trout were fed experimental diets for 120 days followed by processing to obtain boneless skinless fillets. The dietary modification increased concentration of total ω − 3 fatty acids in the fillets, which enhanced chances for lipid oxidation during storage. The fillets were vacuum or non-vacuum packed and stored at 2 °C for 10 or 12 days. Dietary α-TA resulted in higher (P < 0.05) concentration of α-tocopherol in fillets during storage; however, it did not retard (P > 0.05) lipid oxidation. Vacuum packaging resulted in much lower (P < 0.05) TBARS and higher (P < 0.05) retention of α-tocopherol during storage than non-vacuum packaging. However, α-tocopherol unlike vacuum packaging better protected ω − 3 FA in the fillets during storage.     

Radiation induced variability of seed storage proteins in soybean [Glycine max (L.) Merrill]

Soybean variety VLSoy-2 was irradiated with 250 Gy gamma rays to induce variability. A large number of mutants affecting morphological characters were identified and characterized. True breeding mutants obtained were used for studying the variation in seed storage proteins. The mutants M-231, M-17 and M-291 lacked the A₃ subunit of glycinin (11S) protein. Among the three, two mutants M-231 and M-17 were also characterized by the lack of and ′-subunits of β-conglycinin (7S). In addition, the mutant M-291 also showed low levels of trypsin inhibitor activity (TIA) and low levels of and ′-subunits of 7S protein.     

Assessment of protein changes in farmed giant catfish (Pangasianodon gigas) muscles during refrigerated storage

Farmed giant catfish (Pangasianodon gigas) muscles (dorsal and ventral sites) were stored in a refrigerator (at 4 °C) for 14 days to determine the effect of refrigerated storage on biochemical and physical changes. The analyses were carried out at 0, 2, 4, 7, 10 and 14 days of storage. At day 14, Ca²⁺ ‐ATPase activity markedly decreased when compared to its value at day 1 (>90%), while a small decrease was observed for surface hydrophobicity and reactive sulfhydryls content. Total volatile basic nitrogen and trichloroacetic‐soluble peptide content gradually increased when the storage period was extended. The myosin heavy chain decreased slightly on SDS‐PAGE for both meat cuts with increased storage time. Expressible drip and cooking loss were highest during the first day of storage and slightly decreased with storage time. Instrumental hardness was significantly higher in the ventral compared to the dorsal muscle, while the toughness was the highest at the second day of storage. The muscle bundles with scanning electron microscopy were less attached, resulting in the observed big gaps over increasing storage time. Results indicated that changes of proteins have detrimental effects on the quality attributes of farmed giant catfish muscles during refrigerated storage, particularly physical and biochemical properties.     

鲜切红菜薹中有机酸和花青苷在货架贮藏过程中的变化

为探讨货架温度（8±1）℃下鲜切蔬菜中有机酸和花青苷在贮藏过程中的变化趋势,本实验以红菜薹（Brassica campestris L.ssp.chinensis L.var.purpurea Bailey）为材料,采用高效液相色谱/液相色谱-质谱联用（HPLC/HPLC-MS）技术,对红菜薹中有机酸和花青苷的成分和含量进行了鉴定和分析,并对在货架温度下经鲜切处理的红菜薹中有机酸和花青苷在货架期内（7 d）的变化情况进行了观测。结果表明:供试红菜薹中检测出7种有机酸和11种花青苷。其中,苹果酸与柠檬酸是红菜薹中最主要的有机酸（91.49%）;矢车菊-3-p-香豆酰-丙二酰-葡萄糖苷-5-葡萄糖苷和矢车菊-3-阿魏酰-丙二酰-槐糖苷-5-葡萄糖苷是红菜薹中最主要的两种花青苷（65.02%）。鲜切红菜薹中总有机酸含量在货架期内显著下降（p<0.05）,而总花青苷含量呈现先平缓下降后显著上升的趋势（p<0.05）。因此,鲜切红菜薹中所含各有机酸的组分除琥珀酸和富马酸以外在贮藏过程中均呈现不同程度的消解与损失;各花青苷组分在贮藏过程中则大多呈现不同程度的增长。      

Postmortem changes in the adductor muscle of Pacific lions-paw scallop (Nodipecten subnodosus) during ice storage

Postmortem biochemical, chemical, and physical changes of the adductor muscle of Pacific lions-paw scallop were studied during a 15-day storage period at 0 °C (ice). Content of ATP and breakdown products, K value, pH, trimethylamine, total volatile bases, water-holding capacity, colour, and texture changes were examined. K value increased logarithmically (r² = 0.95) from an initial value of 40.3–79.7% on day 15. The spoilage indicators trimethylamine and total volatile bases increased from 15.6 to 30.7 and 1.3 to 6.8 mg N/100 g of sample, respectively, which indicated spoilage at the end of the storage period. Texture, colour, and pH were not affected; however, water-holding capacity decreased significantly, from 96.0% on day 1 to 86.0% on day 15. Overall results indicated that quality of Pacific lions-paw scallop adductor muscle was maintained during at least 12 days of ice storage.     

Biogenic amine changes in barramundi (Lates calcarifer) slices stored at 0 °C and 4 °C

The biogenic amines formation in barramundi (Lates calcarifer) slices kept for 15 days at 0 °C and 4 °C were investigated using nine biogenic amines, total plate counts and biogenic amines formers. Significant differences in biogenic amines concentrations of barramundi slices stored at 4 °C and at 0 °C after 3 days of storage were observed. All amines, except tryptamine, 2-phenylethylamine, tyramine and agmatine in the slices increased with time during storage at both temperatures. At the end of the storage period, histamine concentrations were 82 mg/kg and 275 mg/kg for samples kept at 0 °C and 4 °C, respectively. At day 15, the total plate count was approximately 8.6 log CFU/g for sample kept at 0 °C and 9.7 log CFU/g for samples kept at 4 °C. Histamine-forming bacteria (HFB) in all samples ranged from 5.4 to 6.1 log CFU/g at 0 °C and 4 °C, respectively. The observed shelf-life of barramundi slices were 6–9 days.     

Quality changes in oyster (Crassostrea belcheri) during frozen storage as affected by freezing and antioxidant

Changes in physical, chemical, microbiological and sensory qualities of individual quick frozen (IQF) and contact plate frozen (CPF) oyster (Crassostrea belcheri) meat, treated and untreated with butylated hydroxyanisole (0.02% BHA suspension) during storage at −20 °C for 12 months were investigated. Increase in expressible drip of IQF oyster was slower than that of CPF oyster, due to the fact that quick freezing (IQF) resulted in less tissue damage than slow freezing (CPF). Neither freezing method nor antioxidant treatment caused significant changes in chemical qualities, i.e., pH, moisture, crude protein, crude fat and total volatile basic nitrogen (TVB-N), nor in microbiological qualities, i.e., total viable count (TVC), psychrotrophic bacteria, Escherichia coli and Vibrio parahaemolyticus. During frozen storage, TVC and psychrotrophic bacteria of both BHA-treated and untreated CPF oyster decreased with storage time increases (p < 0.05) at a slower rate than in IQF oyster. Antioxidant treatment could minimise sensory quality changes, especially the colour of frozen oyster during storage.     

Effect of previous frozen storage on quality changes of grass carp (Ctenopharyngodon idellus) fillets during short‐term chilled storage

The effect of chilled, frozen and freeze‐chilled storage on quality of grass carp fillets and soups was evaluated by sensory score, total aerobic counts and biochemical quality. Fish fillets were stored at 4 °C for 6 days (T1), ?40 °C for 12 h and then at ?20 °C for 5 days (T2), ?40 °C for 12 h and then at ?20 °C for 5 days, followed by at 4 °C for 4 days (T3). T1 showed higher sensory score, salt‐soluble protein content, better colour and texture qualities than T2 and T3 within 3 days. All fillets kept good quality based on the acceptable limit of sensory score, total volatile basic nitrogen and total aerobic count during storage time. According to the transportation and retail time, chilled storage is appropriate when it is within 3 days. If it extends for 5 days, freeze‐chilling treatment keeps better quality, but later chilled fillets should be retailed within 4 days.     

Changes of lipids in sardine (Sardinella gibbosa) muscle during iced storage

Changes in lipids of sardine (Sardinella gibbosa) muscle during 15 days of iced storage were investigated. Lipid deterioration, lipolysis and lipid oxidation, occurred throughout the storage. The progressive peroxide formation was monitored by the increase in the absorbance band at 3600–3200 cm⁻¹ in Fourier transform infrared (FTIR) spectra and increased peroxide values were observed in sardine muscle up to 6 days of iced storage, followed by a continuous decrease from then for 9 days (P < 0.05). The increase in thiobarbituric acid reactive substances (TBARS) was noticeable throughout the iced storage (P < 0.05). However, no difference in conjugated diene (CD) of sardine muscle was found within the first 12 days of iced storage (P > 0.05). Marked decreases in unsaturated fatty acids, especially eicosapentaenoic acid (EPA; C20:5(n − 3)) and docosahexaenoic acid (DHA; C22:6(n − 3)) were observed as the storage time increased. Those changes indicated that lipid oxidation occurred in sardine muscle. A gradual increase in free fatty acid formation, with decreases in triglyceride and phospholipid contents, was found during iced storage (P < 0.05), suggesting hydrolysis induced by lipases and phospholipases.     

Physicochemical characterisation of gulupa (Passiflora edulis Sims. fo edulis) fruit from Colombia during the ripening

Gulupa (Passiflora edulis Sims. fo edulis) is a tropical fruit native to America. This study was undertaken to characterize the physicochemical properties of this fruit in three maturity stages. In all stages, the pH, °Brix, texture, and titratable acidity were determined. pH value and solid soluble content increased during ripening and titratable acidity decreased during this process; in contrast, texture values did not show significance variance. It was confirmed the presence of cyanidin-3-O-??-D-glucopyranoside as major anthocyanin. The changes on colour were followed by tristimulus colorimetry using image analysis, a very useful new approach for the measurement of non-homogeneous colours. By using PCA (Principal Component Analysis), clusters of data corresponding to each stage could be defined. Additionally, the volatile composition was followed by HS-SPME (Headspace-Solid Phase Microextraction) and GC/MS (Gas Chromatography/Mass Spectrometry) analyses. The results showed an increase in the amount of volatile during fruit ripening, with aliphatic esters as major constituents.     

Structural changes in sardine (Sardina pilchardus) muscle during iced storage: Investigation by DRIFT spectroscopy

Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy has been used for the first time to evaluate the postmortem changes in structure of components from sardine muscle in relation to quality loss. Sardines (Sardina pilchardus) were stored in ice for up to thirteen days. The spectroscopic study was focussed on the structural changes produced on the lipids and proteins.     

Chemical and sensory quality changes of fish fingers,made from mirror carp (Cyprinus carpio L., 1758), during frozen storage (−18 °C)

The effects of frozen storage at −18 °C on the chemical and sensory qualities of fish fingers produced from unwashed and washed mirror carp (Cyprinus carpio) mince were investigated. The amounts of moisture, crude protein, lipid, crude ash, ω3 polyunsaturated fatty acids (PUFA ω3), and ω6 polyunsaturated fatty acids (PUFA ω6) in fish fingers produced from unwashed mince (UWF) were found to be 68.50%, 15.5%, 6.00%, 2.20% 2.31%, and 55.2%, respectively, while they were found to be 70.23%, 10.8%, 2.14%, 1.80%, 2.28%, and 54.6%, respectively, in carp fingers produced from washed mince (WF). The thiobarbituric acid value (TBA, mg malonaldehyde/kg) was found to be significantly higher in mince of WF than in mince of UWF and increased significantly during frozen storage in both the mince of UWF and WF (p < 0.05). A significant decrease in pH was obtained throughout the washing treatment (p < 0.05). There were no significant differences of pH in either the mince of UWF or WF between the beginning and end of the storage periods (p > 0.05), whereas a sharp increase was observed in the fourth month in both groups. The protein solubilities of the mince of both UWF and WF decreased significantly throughout the storage periods (p < 0.05). Sensory parameters of colour, odour, flavour, and general acceptability for both groups decreased during the frozen storage period (p < 0.05) but were still within acceptable limits. It was also concluded that mirror carp was a good source for fish fingers and that product could be stored for five months in a frozen state without undesirable changes of sensory and chemical qualities.     

Kinetics of tocols degradation during the storage of einkorn (Triticum monococcum L. ssp. monococcum) and breadwheat (Triticum aestivum L. ssp. aestivum) flours

The kinetics of tocols degradation in wholemeal and white flours from einkorn cv Monlis and bread wheat cv Serio were studied during storage at five different temperatures (−20, 5, 20, 30 and 38 °C) up to 242 days. Tocols decreased as a function of time and temperature, following first-order kinetics. Degradation rates and their dependence upon temperature were similar for the two Triticum species studied. Tocols decrease was quicker in white flour than in wholemeal flour (on average for total tocols at 38 °C, k = 7.79 × 10⁻³ days⁻¹ vs 3.15 × 10⁻³ days⁻¹, respectively). The temperature-dependent degradation was similar for all homologues (Ea = 34.3–49.4 kJ/mol) except for α-T, less thermostable in white flours (Ea = 61.2 kJ/mol in einkorn and Ea = 54.7 kJ/mol in bread wheat).