Quality and storage stability of extruded puffed corn-fish snacks during 6-month storage at ambient temperature

BACKGROUND: Cereal‐based snacks are usually low in protein and other nutrients. Increased health awareness of consumers has led the food industry to develop fortified snacks with functional ingredients. Three types of extruded corn‐fish snacks, containing 150 g kg^?1 carp mince and 150 g kg^?1 trout mince, 30 g kg^?1 freeze‐dried saithe protein and a regular corn snack (control). were produced to study quality changes and storage stability of the products during 6‐month storage at 27 ± 2 °C. RESULTS: All products had the same level of water activity and proximate composition except for protein. Fortified snacks had a protein content of 93–98 g kg^?1, compared with 65 g kg^?1 in the control. A significant increase was observed for peroxide value during storage (0.0 to 2.8 meq kg^?1). Scores for attributes describing oxidation and off odors and flavors increased after 5–6 months' storage but attributes describing puffed corn snack odor and flavor did not change during storage of any of the products. CONCLUSION: Extrusion of corn grits with fish flesh/fish protein can be used to produce high‐protein products that would be an option to provide nutrient snacks for consumers and to increase fish consumption. Copyright © 2011 Society of Chemical Industry     

Evolution of major and minor components and oxidation indices of virgin olive oil during 21 months storage at room temperature

This article reports the evolution of major and minor components and oxidation indices of seven samples of virgin olive oil (VOO) which differ in their initial contents of natural antioxidants, during 21 months of storage at room temperature and in darkness. As expected, statistically significant differences in the antioxidant contents were observed, with initial concentrations ranging from 0.33 to 0.55 mmol/kg for α-tocopherol and from 1.08 to 3.88 mmol/kg for total phenols. The quality indices PV, K₂₃₂ and K₂₇₀ increased linearly during the storage time studied (21 months), which should make it possible to predict the shelf-life of a VOO sample by extrapolation from the results obtained during a relatively short period of storage (i.e. several weeks). K₂₃₂ was the first parameter that exceeded the established upper limit for extra VOO and therefore seems to be the most relevant index for analysis and monitoring to determine the commercial category of the olive oil. The reduction of total phenolic compounds ranged from 43% to 73%, and it was remarkable that the decrease was higher in samples whose initial phenol contents were greater. Hydroxytyrosol increased linearly in most samples, whereas its complex forms decreased considerably, with the exception of two in which the hydroxytyrosol content decreased continuously or diminished after an initial increase. This fact was probably due to the low initial concentration of hydroxytyrosol secoiridoid forms: i.e. 0.32 mmol/kg for the sum of 3,4-DHPEA-EDA and 3,4-DHPEA-EA in one of these samples as compared to between 0.65 and 2.06 mmol/kg in the others. Finally, there was a slight and apparently linear fall in the α-tocopherol content of all samples, with a reduction ranging from 0.054 mmol/kg (12%) to 0.127 mmol/kg (23%), although there may be a short lag phase at the beginning of the assay.     

1-MCP suppresses ethylene biosynthesis and delays softening of 'Hami' melon during storage at ambient temperature

BACKGROUND: ‘Hami’ melon is susceptible to softening during postharvest storage at ambient temperature, which enhances postharvest deterioration and limits transportation and storage. To look for a method of softening control, the effect of 1‐methylcyclopropene (1‐MCP) on regulating postharvest softening of ‘Hami’ melon fruit was investigated. RESULTS: 1‐MCP treatment at 1 µL L^?1 significantly reduced ethylene production and maintained higher levels of fruit firmness. It also markedly inhibited the accumulation of 1‐aminocyclopropane‐1‐carboxylic acid (ACC) and maintained lower activities of ACC synthase and ACC oxidase. In addition, 1‐MCP treatment reduced the activities of fruit‐softening enzymes such as pectin methyl esterase, polygalacturonase, endo‐1,4‐β‐glucanase and β‐galactosidase. CONCLUSION: 1‐MCP was effective in suppressing ethylene production and delaying fruit softening in ‘Hami’ melon by decreasing the activities of ethylene biosynthesis enzymes and inhibiting fruit‐softening enzymes. Copyright © 2011 Society of Chemical Industry     

Changes in biogenic amines during iced and ambient temperature storage of tilapia

BACKGROUND: Changes in the biogenic amine content of tilapia (Oreochromis mossambicus) with time during iced and ambient temperature (28 °C) storage were quantified by high‐performance liquid chromatography in a gradient elution system using acetonitrile and water as solvents. RESULTS: The levels of amines in tilapia were significantly low even after a long storage period (18 h under ambient temperature storage and 15 days under iced storage). All amines except spermidine and spermine increased with time during both iced and ambient temperature storage. Spermidine and spermine showed a decrease with increasing storage time. CONCLUSION: Being euryhaline (tolerant of a wide range of salinity) in nature, tilapia shows significantly low quantities of biogenic amines even after a long period of ambient temperature or iced storage, unlike most other marine fish. Copyright © 2008 Society of Chemical Industry     

Prediction of microbial growth in fresh-cut vegetables treated with acidic electrolyzed water during storage under various temperature conditions.

Effects of storage temperature (1, 5, and 10 degrees C) on growth of microbial populations (total aerobic bacteria, coliform bacteria, Bacillus cereus, and psychrotrophic bacteria) on acidic electrolyzed water (AcEW)-treated fresh-cut lettuce and cabbage were determined. A modified Gompertz function was used to describe the kinetics of microbial growth. Growth data were analyzed using regression analysis to generate "best-fit" modified Gompertz equations, which were subsequently used to calculate lag time, exponential growth rate, and generation time. The data indicated that the growth kinetics of each bacterium were dependent on storage temperature, except at 1 degrees C storage. At 1 degrees C storage, no increases were observed in bacterial populations. Treatment of vegetables with AcEW produced a decrease in initial microbial populations. However, subsequent growth rates were higher than on nontreated vegetables. The recovery time required by the reduced microbial population to reach the initial (treated with tap water [TW]) population was also determined in this study, with the recovery time of the microbial population at 10 degrees C being <3 days. The benefits of reducing the initial microbial populations on fresh-cut vegetables were greatly affected by storage temperature. Results from this study could be used to predict microbial quality of fresh-cut lettuce and cabbage throughout their distribution.     

Effect of extrusion conditions on iron stability and physical and textural properties of corn snacks enriched with soybean ferritin

Soybean sprouts cultured in 20 mm FeSO₄ were introduced into corn snacks (1.75–3.50%) to supplement iron. The effect of extrusion process on the ferritin iron stability and on product quality was studied. Iron stability in these fortified snacks depended mainly on feed moisture levels, with the best results seen when the feed moisture and temperature were 12% and 110 °C, respectively. Lower feed moisture was beneficial to hardness, expansion ratio and bulk density, while lower temperature increased snack hardness and density, while worsening the expansion ratio. The snacks’ water absorption was strongly and directly dependent on the temperature, while their solubility mainly depended inversely on feed moisture. All of the variables tested altered the colour of the snacks. The conditions that were best for producing the ferritin‐fortified snacks – 12% feed moisture, and temperature equal than or less to 140 °C – may yield a product with the desired quality features.     

Aging kinetics of low amylose rice during storage at ambient and chilled temperatures

The objectives of this study were to monitor the changes in rice properties during aging and to compare kinetic parameters related to some of those changes. Paddy of three low amylose rice varieties was stored at ambient (30 ± 2ºC) and chilled (8 ± 2ºC) temperatures for 9 and 18 months, respectively. Aging led to a decrease in solid loss, peak viscosity, breakdown, and adhesiveness and an increase in head rice yield, minimum cooking time, water uptake, volume expansion, pasting temperature, final viscosity, through viscosity, setback, and hardness. Low temperature storage efficiently retarded those changes. Data of the time-dependent changes in hardness, adhesiveness, pasting temperature, peak viscosity, and breakdown of all samples stored at 30°C were fitted well with the first-order fractional conversion kinetic model (R² = 0.77 – 0.98). Higher storage temperature resulted in greater rate constant (k; up to 9 times higher) of those changes.     

The effect of rice bran on physicochemical,textural and glycaemic properties of ready-to-eat extruded corn snacks

In this work, corn extruded snack products were enriched with rice bran (RB) at 10% and 15%. A co-rotating twin-screw extruder was used with a feed moisture content of 16 g 100 g⁻¹, a screw speed of 240 r.p.m. and four heating sections of the barrel (100, 140, 150 and 150 °C). The impact of RB inclusion on nutritional profile, starch digestion, physicochemical and textural properties of snack products was evaluated. RB-enriched extrudates showed a lower specific volume and hardness and higher crispness than control. RB at 15% gave a water-holding capacity lower than control. Rheology of extrudate dispersions indicated an increase in elastic interactions and solid-like behaviour with RB supplementation. Differences in rheological properties resulted in attenuation of predictive glycaemic response for RB-enriched snacks.     

Impact of storage at room temperature on the properties of CiP solutions

This work reports the analysis of cleaning solutions used in cleaning in place (CiP) and the changes that occur during storage at room temperature. Tests were performed on different solutions used to clean brewhouse vessels and a mash filter in a local brewery. The solutions were collected from CiP tanks after regeneration and were stored for three months in darkness at room temperature. Over time, the physical, chemical and microbiological parameters of the cleaning solutions were analysed. At the end of the study, the solutions were evaluated in terms of surface wetting and cleaning capability. The results showed that storage of the solutions at room temperature contributed to the agglomeration of particulates into larger conglomerates that may contribute to clarification of cleaning solutions by sedimentation. However, other parameters of the stored CiP solutions did not change. © 2019 The Institute of Brewing & Distilling     

Antioxidant effects of rosemary extract and whey powder on the oxidative stability of wiener sausages during 10 months frozen storage

Twelve (Large White×Landrace) gilts were randomly allotted in a 2×2 factorial design with the respective factors being dietary vitamin E (10 or 200 mg/kg feed) and dietary fishmeal (0 or 5%). Wiener sausages were manufactured with or without antioxidants such as rosemary extract and sweet whey powder from meat obtained from the animals after slaughter and stored for 5 days at 4?°C. The oxidative stability of the wieners was examined over ten months of frozen storage. Lipid oxidation in the product was measured by means of thiobarbituric acid reactive substances (TBARS) and fluorescence shift. Sensory evaluation of the product to detect oxidative changes was also carried out. The fluorescence shift method was unsatisfactory in the case of wieners containing rosemary extract, as it appeared that the extract contained compounds that fluoresced and therefore interfered with the method. No lipid oxidation as measured by TBARS, fluorescence shift and sensory analysis was observed in wieners stored at -20?°C for 10 months. The oxidative stability of wieners was unaffected (P>0.05) by dietary treatments or by the addition of antioxidants. The high oxidative stability of the wieners, even in the absence of antioxidants, could be due to sodium erythorbate present in the formulation as an additional antioxidant.     

储藏温度对玉米胚芽和胚乳生理变化的影响

以黑育I号玉米为试材,研究不同温度对玉米储藏品质的影响。结果表明:随着储藏时间的延长,玉米蛋白质、淀粉和脂肪含量逐渐下降,脂肪酸值增加。低温储藏可明显延缓玉米营养物质的流失速度,抑制α-淀粉酶和脂肪酶活力。储藏22 d后,在20℃储藏的玉米的α-淀粉酶和脂肪酶活力分别为在-18℃储藏的玉米的2.3和4.4倍。     

The storage of herring (Clupea harengus) in ice,refrigerated sea water and at ambient temperature. Chemical and sensory assessment

Herring caught during the winter and summer were stored in ice, refrigerated sea water (RSW) and at ambient temperature. Chemical tests and a sensory assessment of the fish were made on samples stored for up to 13 days. Results indicate that herring can be chilled simply and rapidly using an RSW plant and that spoilage changes in the fish stored in ice and RSW are similar during the first 4 or 5 days of storage. The chemical tests investigated serve more as indicators of spoilage rather than quantitative guides.     

香辛料提取物对牛肉丸冻藏过程中质构和微观结构的影响

以牛肉丸保水性、质构特征和微观结构为评价指标,探讨了迷迭香、丁香和桂皮提取物对牛肉丸冻藏过程中食用品质的影响。结果表明,牛肉丸在冻藏过程中,解冻损失和蒸煮损失逐渐增加(p<0.05),说明牛肉丸的保水性降低,而添加迷迭香、丁香和桂皮提取物能显著提高保水性(p<0.05);牛肉丸的硬度和弹性随着冻藏时间的延长,先增加后降低,添加迷迭香、丁香和桂皮提取物能显著提高牛肉丸的硬度和弹性(p<0.05),改善其质构特性;迷迭香、丁香和桂皮提取物能改善冻藏导致的牛肉丸组织结构松散、粗糙和不规则现象。香辛料提取物具有改善牛肉丸制品食用品质的潜在应用价值。      

热激处理对黄瓜低温贮藏特性的影响

为研究热激处理对低温贮藏中黄瓜冷害发生的防治效果及对贮藏特性的影响,以"金田208"黄瓜为试材,通过测定黄瓜果实硬度、可溶性固形物、失重率、腐烂率、冷害指数、相对电导率、丙二醛含量、VC含量、叶绿素和可溶性蛋白含量,确定黄瓜适宜的热激处理条件。结果表明:不同的热激方式、处理温度及时间会对黄瓜造成不同的影响。不适宜的热水处理会造成大量霉变,不适宜的热空气处理则会出现不同程度的失水、褪绿或烫斑。适宜的热水和热空气处理均可以对黄瓜的冷害起到推迟或减轻的效果,并有效的控制低温贮藏期间黄瓜果实的失水,能够延缓黄瓜细胞膜渗透率的增加和MDA的积累,防止可溶性蛋白含量降低。利用42℃的热水处理10min可以显著(p0.05)降低黄瓜的冷害指数和腐烂率,延缓果实硬度、可溶性固形物的下降,并维持较低的丙二醛(MDA)含量和相对电导率,对减轻黄瓜冷害症状起到了较好效果,适宜用作黄瓜的热激处理条件。     

热激处理对黄瓜低温贮藏特性的影响

为研究热激处理对低温贮藏中黄瓜冷害发生的防治效果及对贮藏特性的影响,以\     

Growth inhibition and inactivation of Alicyclobacillus acidoterrestris endospores in apple juice by hyperbaric storage at ambient temperature

Control of endospores of Alicyclobacillus acidoterrestris in pasteurized apple juice using hyperbaric storage at 18 to 23 °C was compared to storage at atmospheric pressure and 18 to 23 °C, as well as refrigeration at ~4 °C for up to 30 days. The juice samples were inoculated with approximately 1 × 10⁵ CFU/mL spores. The juice spoiled quickly at atmospheric pressure and ambient temperature, while under refrigeration spore levels remained unchanged for 30 days. Hyperbaric storage of inoculated apple juice at 25, 50 and 100 MPa at 18 to 23 °C resulted in spore inactivation at more rapid rates as pressure magnitudes increased, reaching levels below the detection limit of 10 CFU/mL at 50 and 100 MPa. In highly acid foods such as apple juice, hyperbaric storage at pressures ≤100 MPa and ambient temperature was effective in inactivating spores of A. acidoterrestris for periods up to 30 days.These results indicate hyperbaric storage at ambient temperature as a clearly more efficient preservation procedure to control the development of A. acidoterrestris endospores, compared to ambient temperature and refrigerated storage, in highly acidic foods as apple juice.