Degradation of quality attributes of sweetened Julie and Ogbomoso mango juices during storage

Changes in the quality attributes of sweetened Julie and Ogbomoso mango juices were investigated. Sweetened mango juices were processed, bottled and stored at 25 °C for 12 weeks. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents were evaluated immediately after processing and subsequently at 2-week intervals. The L*, a* and b* (HunterLab) parameters were determined to evaluate colour changes due to non-enzymatic browning.Generally, the quality attributes of the sweetened mango juices decreased during storage. The titratable acidity, pH, total solids, ash, soluble solids and ascorbic acid contents decreased during storage. After 12 weeks of storage, the percentage ascorbic acid loss of sweetened Julie and Ogbomoso mango juices was 16.25 and 16.67%, respectively. Browning index, chroma and b* values increased during storage. Colour changes in sweetened mango juices were mainly due to b* value and chroma.     

Correlations of carotene with sensory attributes in carrots under different storage conditions

The all-trans-α-, all-trans-β-, and cis-carotene content, measured by HPLC–DAD and the main sensory attributes in two carrot varieties, of the years 2002 and 2003, during storage at 4 °C, 20 °C, −18 °C and −25 °C were determined. At 4 °C, increase of the total carotene content of 8% and 23% were found in the 1st and in the 2nd harvest year, respectively within 14 days of storage. Deep-frozen carrots were characterized as more “juicy”, less “tender”, “aromatic” and “sweet” compared to fresh carrots in both harvest years. Sensory attributes and chemical data were correlated, and it was shown that the carotene content was positively correlated with the attribute fibrous texture and negatively correlated with the attribute tender texture.     

Soybean seed storage: Packaging technologies and conditions of storage environments

Artificial refrigeration is sufficient for maintaining the quality of soybean seeds in storage in processing plants, but when lots are distributed to rural producers, they are often kept in natural environments, without temperature or relative humidity control, which decreases their germination rates. This research aimed to evaluate different storage conditions and technological packaging for soybean seeds. The first stage evaluated the quality of soybean seeds stored at different temperatures for up to one year in raffia bags with or without polyethylene inner liners. The second stage evaluated the quality of soybean seeds stored in a natural atmosphere in raffia or laminated packaging, in a modified atmosphere with polyethylene packaging, in a refrigerated atmosphere with raffia or laminated packaging, or in a modified and refrigerated atmosphere with polyethylene packaging. An increase in storage time had a negative influence on the quality of the stored seeds. Storage temperature was the main influence in the reduction in seed physiological quality. Storage of soybean seeds in raffia packaging coated with polyethylene in a natural-temperature environment resulted in seeds retaining similar physical and physiological qualities to those stored under refrigeration. Raffia packaging coated with laminated material maintained the best physical and physiological quality of soybean seeds stored over time. Optimal packaging technology with laminated coating in “big bag” format has replaced the conditioning of storage environments with the maintenance of the quality of soybean seeds over time. The packaging technology is an excellent alternative for the soybean processing units.     

Effects of state/phase transitions on the quality attributes of mango (Mangifera indica L.) during frozen storage

Effects of different state/phase transitions (temperature fluctuations) on quality attributes of mango cubes during frozen storage were investigated. Temperature of frozen mango was modulated from ?65 °C to different states, namely, rubbery state , partially freeze‐concentrated state () and glassy states ( and ). Results revealed that frozen samples after 4 weeks of storage in a glassy state showed higher quality in hardness, drip loss, colour and ascorbic acid. Quality of mango still continued to change during frozen storage even in the glassy state without temperature fluctuations. Furthermore, there was a significant decrease in quality attributes of frozen mango subjected to temperature fluctuations above and . Current work indicates glassy state storage can improve retention of quality attributes in frozen mango and glassy state without temperature fluctuation was proposed as the most favourable frozen storage condition.     

Limiting the deterioration of mango fruit during storage at room temperature by oxalate treatment

Effects of oxalate on the incidence of decay and ripening in mango fruit, and its physiological effects on the peel and flesh of mango were investigated after mango fruit (Mangifera indica L.) were dipped in different oxalate solutions for 10 min and then stored at 25 °C. Oxalate application decreased the incidence of decay and delayed the ripening process in mango fruit during storage. Potassium oxalate treatment resulted in increased activities of peroxidase (POD) in both the peel and the flesh and polyphenol oxidase (PPO) in the peel, without activation of phenylalanine ammonia-lyase activity, and elevated total phenolic content in the peel. The physiological effects of oxalate in increasing activities of POD and PPO and elevating total phenolic level could be involved in induced resistance of mango fruit against postharvest disease. Oxalate application could be a promising method to suppress postharvest deterioration and extend the useful shelf-life of mangoes.     

Changes in physicochemical properties of organic hulled rice during storage under different conditions

Effects of packaging materials, storage temperatures and time on physicochemical properties of organic hulled red fragrant rice cv. Hom Daeng were investigated. The samples were vacuum-packed in oriented polypropylene/aluminium/linear low-density polyethylene or nylon/linear low-density polyethylene pouches and stored at ambient temperature or 15 °C for up to 12 months. Results from differential scanning calorimetry indicated that onset and peak temperature of gelatinisation of the aged rice samples increased after the 6th month while enthalpy of gelatinisation initially increased and then decreased after the 8th month. Measurements from the Rapid Visco Analyzer revealed that peak viscosity and breakdown of the rice pastes increased within the first 2 months, then decreased after the 6th month, whereas setback gradually increased during storage. Swelling power, at 70 and 90 °C, of the aged samples, tended to decrease after the 4th month. Lower storage temperature retarded those changes while packaging materials did not influence the changes. Changes in thermal and pasting properties of the aged samples were reversed after adding 2-mercaptoethanol. Hence, an increase in disulphide linkages of oryzenin during storage could play a crucial role in altering those properties. Sensory evaluation indicated a significant increase in hardness of the cooked rice prepared from the longer-aged samples (p ? 0.05). However, the cooked rice samples, deriving from the samples stored at ambient temperature for up to 12 months, were still acceptable for Thai consumers.     

贮藏条件与禽蛋品质的相关性研究

为了比较不同贮藏条件对禽蛋品质的影响,将鸡蛋、鸭蛋和鹅蛋置于5、10、20、30℃贮藏30d,分析3种禽蛋品质变化与贮藏条件相关性规律。结果表明:贮藏温度对禽蛋品质的影响显著,高温贮藏加速禽蛋品质下降;禽蛋品质随贮藏时间延长而下降;除哈夫单位,3种禽蛋品质可以用相同品质指标来衡量。拟合方程的判定系数表明,贮藏过程中失重率和整蛋pH变化可以用零级反应动力学方程表征,哈夫单位和蛋黄指数变化规律可以用一级反应动力学方程表征。品质变化动力学级数与禽蛋品种无关,不同种类禽蛋在贮藏过程中品质变化规律基本相似。     

Correlations of ingredients with sensory attributes in green beans and peas under different storage conditions

The total ascorbic acid contents and the antioxidant capacity in green beans and in peas were measured during deep-frozen storage and compared to storage at 4 °C and 20 °C. In green beans only, the flavonols quercetin and kaempferol were measured. The results were correlated with sensory attributes which were evaluated at the same storage stages. The total ascorbic acid content is a good parameter for the storage time of both vegetables and showed, for peas, a positive correlation with the attribute “sweet taste” and a negative correlation with the attribute “musty” odour. The total ascorbic acid content of green beans was positively correlated with a “squeaky” texture and negatively with a “musty” taste. The flavonol content and the antioxidant capacity were more stable during the storage process and showed less correlation with sensory attributes.     

Effects of fining treatment and storage temperature on the quality of clarified banana juice

The clarified banana juice was subjected to different treatment namely bentonite, combination of gelatin and bentonite and control and stored at 4, 25 and 37 °C for 24 weeks. The effects of fining treatment, storage temperature and storage time on turbidity, total polyphenol, browning index, microbiological, and sensory quality of clarified banana juice were evaluated during storage. Fining treatment, storage temperature and storage time had a significant (p<0.001) effect on turbidity, total polyphenol and browning index of clarified banana juice. Turbidity and browning index of juice were reduced by fining treatment with bentonite and a combination of gelatin and bentonite but increased with storage temperature and storage time. A significant decrease in total polyphenol content and increase in turbidity and browning index were detected for all juice samples during storage. However, it was noted that changes were significantly greater in control juice stored at higher temperature than in juice stored at 4 or 25 °C for up to 6 months. Sensory evaluation revealed that juices treated with bentonite or a combination of gelatin and bentonite and stored at 4, 25 or 37 °C were acceptable for up to six months, whereas untreated juice stored at 37 °C was only acceptable for up to 16 weeks.     

果胶酶和纤维素酶对芒果出汁率及品质的影响

为提高芒果的出汁率,采用果胶酶和纤维素酶对芒果浆进行酶解,通过正交实验研究了果胶酶添加量、纤维素酶添加量、酶解温度、酶解时间4个因素对芒果出汁率的影响。结果表明:当果胶酶添加量为0.01%、纤维素酶添加量为0.007%、酶解时间为60min、酶解温度为40℃时,芒果的出汁率最高,达到71.15%;酶解得到的芒果汁可溶性固形物为16.7%±0.1%,可滴定酸为0.51%±0.08%,类胡萝卜素为(1.23±0.07)mg/100g,还原糖为7.6%±0.08%,果胶含量为(357±1.32)mg/100g,保留了鲜芒果的营养成分。     

贮藏条件对葡萄酒中白藜芦醇的影响

采用HPLC方法研究贮藏条件(贮藏温度、光照)对葡萄酒中四种白藜芦醇异构体含量的影响,发现:1)高温贮藏条件引起白藜芦醇总量的降低,其中反式白藜芦醇减少了45.8%;2)日光照射引起白藜芦醇含量的降低,而灯光照射后白藜芦醇总量未见明显降低;3)光照具有促进白藜芦醇向白藜芦醇糖苷转化的趋势.实验结果证明高温贮藏不利于葡萄酒中白藜芦醇的保存,商业流通中的灯光照射对葡萄酒中白藜芦醇含量无明显影响.     

Osmotic dehydration pretreatment for improving the quality attributes of frozen mango: effects of different osmotic solutes and concentrations on the samples

The effect of osmotic dehydration pretreatment on the quality attributes (e.g. colour, hardness, drip loss, vitamin C content and pH) of frozen mango cuboids in different osmotic solutions (sucrose, glucose and maltose) and concentrations (30, 45 and 60% (wt/wt)) was investigated. Results revealed that melting temperature of mango cuboids was affected by both solute type and solid mass fraction. In addition, the dehydrofrozen samples pretreated in maltose had higher quality in vitamin C content (increasing by 23.5–73.0%), colour (colour change reducing by 2.6–39.2%) and drip loss (reducing by 0.7–9.7%) than those pretreated in other osmotic solutions. The cuboids pretreated in glucose displayed higher hardness (increasing by 16.4–36.2%). Based on principal component analysis and group distance, osmotic dehydration in 45% maltose was proposed as the most favourable freezing conditions with the highest sensory score (6.8). The current work indicates osmotic dehydration significantly improves frozen mango quality.     

液氮冻结对冻藏雷竹笋品质的影响

目的 研究液氮的3种冻结温度和冻结至3种中心温度对冻藏雷竹笋品质的影响。方法 测定不同液氮冻结温度和中心温度的冻藏雷竹笋的汁液流失率、可溶性固形物和粗纤维含量、硬度、色差、挥发性风味物质和感官评分。结果 液氮冻结温度组中,-60℃组冻结雷竹笋的感官评分、硬度显著低于-90、-120℃组（p<0.05）,而汁液流失率、粗纤维含量、a*值显著高于-90、-120℃组（p<0.05）;雷竹笋原有挥发性风味物质的信号强度为：-120℃>-90℃>-60℃,冻藏过程中产生的挥发性风味物质的信号强度为：-120℃<-90℃<-60℃。中心温度组中,-6℃组冻结雷竹笋的感官评分、硬度显著低于-12、-18℃组（p<0.05）,而汁液流失率、粗纤维含量、a*值、b*值显著高于-12、-18℃组（p<0.05）;雷竹笋原有挥发性风味物质的信号强度为：-18℃>-12℃>-6℃,冻藏过程中产生的挥发性风味物质的信号强度为：-18℃<-12℃<-6℃。-12℃和-18℃组冻藏雷竹笋品质差异不显著。结论 降低液氮冻结温度加快了冻结速率,维持了冻藏雷竹笋较好的感官品质;冻结至中心温度-12℃时,雷竹笋内部大部分水分已完成冻结,此时转移至-18℃冰柜中对雷竹笋组织内部影响不显著（p>0.05）。     

Ensuring the best storage temperature of Egyptian pastrami based on microbiological,physico-chemical and sensory evaluation

Egyptian pastrami is among the most important and widely consumed meat products in Egypt and due to the great defects in its storage as a ready-to-eat products by retailers, distributers or even consumers, the aim of the current research is to assess the effect of storage temperatures on physico-chemical, microbiological, and sensory properties of Egyptian pastrami using autoclaved non-meat ingredients to ensure the best storage temperature of such important food. Four storage temperatures were applied including room temperature during summer (25 °C), room temperature during winter (15 °C), in fridge at 4 °C and in freezer at −18 °C for a period of 60 days using whole unsliced produced pastrami arms. The findings showed that there was no significant effect (P > 0.05) of storage temperatures on the physico-chemical and sensory properties of tested Egyptian pastrami as the four types were highly accepted based on the physico-chemical and sensory evaluation. Meanwhile, there was noticeable effect of storage temperatures on the microbiological properties of the four manufactured types of pastrami, as the samples stored at −18 °C or at 4 °C for 60 days had the lowest microbial loads and was the best from microbiological aspect.     

Effects of temperature on the ripening of mango fruit (mangifera indica L. var. tommy atkins)

The effects of temperature on the ripening of Tommy Atkins mango were studied. Ripening temperature can affect fruit colour, flavour and texture development differently. Fruits at 12°C did not ripen to full eating quality during the 16 days of the experiment. Sugar levels were comparable with those at other temperatures, but acid levels were higher; they retained some green coloration, had lower pulp carotenoids and showed incomplete softening. After 15 days at 17°C, fruits had softened and degreened to an acceptable level but had a poor pulp colour. They were comparatively high in sugars but were also high in acids, resulting in a low sugar:acid ratio. Fruits kept at 22, 27 and 32°C all showed the development of good quality characteristics of high chlorophyll breakdown, high pulp carotenoids, a good texture and a balanced sugar: acid ratio. Similar characteristics were shown at 37°C, although the peel generally appeared mottled and the pulp had slightly lower sugar:acid ratios.     

Induction of apoptosis by ethanolic extract of mango peel and comparative analysis of the chemical constitutes of mango peel and flesh

The underlying mechanisms of the anticancer activity of the ethanolic extract of mango peel (EEMP) and its constituents were investigated. EEMP induced death of human cervical carcinoma HeLa cells through apoptosis, as evidenced by the increased cell population in the sub-G1 phase and the appearance of fragmented nuclei. Treatment of the cells with EEMP also downregulated anti-apoptotic Bcl-2 expression, resulting in the proteolytic activation of caspase-3, 7, 8, and 9 and the degradation of poly (ADP-ribose) polymerase (PARP) protein. The major components of mango peel were identified by liquid chromatography–electrospray ionisation tandem mass spectrometry and gas chromatography–mass spectrometry. Our data suggest that EEMP is an excellent source of quercetin 3-O-galactoside, mangiferin gallate, isomangiferin gallate, quercetin-3-O-arabinopyranoside, and mangiferin along with unsaturated fatty acids oleic acid, linoleic acid, and ethyl linoleate, which may help to prevent cervical cancer and may be a useful agent for the treatment of some other malignancies.     

Expression of expansin gene, MiExpA1, and activity of galactosidase and polygalacturonase in mango fruit as affected by oxalic acid during storage at room temperature

An expansin gene, MiExpA1, from mango fruit (Mangifera indica L. cv. Zill), which had highest homology with MiExpA1 from cv. Dashehari by 96.43% in nucleotide sequence and 95.79% in amino acid sequence, was cloned and characterised. Moreover, effects of oxalic acid on MiExpA1 expression and enzymatic activities of α-galactosidase (α-Gal), β-galactosidase (β-Gal), and polygalacturonase (PG) were investigated after Zill fruit were dipped in 5 mM oxalic acid solution for 10 min and then stored at 25 °C. Application of oxalic acid significantly inhibited decrease in flesh firmness, notably suppressed and delayed MiExpA1 expression in the peel and the flesh, and also significantly decreased activities of these pectolytic enzymes in the flesh. It was suggested that these effects of oxalic acid might collectively contribute to alleviating cell wall disassembly, thereby slowing the process of softening and ripening in mango fruit during storage.     

贮存温度和时间对山楂汁品质的影响

目的:研究不同储藏温度下山楂汁中组分及品质的变化情况。方法:将同一浸提工艺得到的山楂汁,分别在4、25、37℃下放置,每隔2、4、6、8、10d取样测定,以透光率、总色度、可溶性固形物、蛋白质含量、总酸、有机酸为考察指标,研究不同温度下各参数的变化规律。结果:透光率、总色度、褐变度、褐变指数随温度升高而升高;相同贮存温度下,随着贮存时间的延长,可溶性固形物的含量逐渐降低,最后趋于平稳。相同贮存时间下,37℃条件下贮存的山楂汁的蛋白质含量略有下降,4℃和25℃条件下储藏的山楂汁的蛋白质含量下降幅度较大,最后趋于稳定。原始山楂汁液中总酸的含量为24.27g/kg,随着贮存时间的延长,37℃贮存下山楂汁中总酸的降幅最大,较起始阶段降低13.1%;结论:相同贮存条件下,山楂汁透光率、总色度、褐变度、褐变指数均与温度成正相关;相同贮存时间下,低温条件固形物含量相对较高,一定程度上可以降低蛋白质含量而更加有利于汁液的稳定性;低温贮存能更好的保留山楂汁中的有机酸以及更大程度的保证山楂汁的口感。      

Effect of microwaves on rice quality

The effect of microwave radiation on rice quality was investigated using an industrial continuous microwave oven. Effects of microwave treatment, packaging method and storage time on rice quality during storage were assessed. Water content, free fatty acid content and protein content were reduced but the blue value (BV) of rice and the sensory quality of cooked rice increased as microwave-energy consumption increased. Qualities of both microwave-treated and untreated rice changed during storage, but the changes were less in the treated rice sample. Differences in the protein content, fat content and total sugar content between the microwave-treated and untreated rice were significant at the beginning of storage but not after storage for more than 120 days. Variance analysis showed that rice storage qualities were significantly affected by treatment methods and storage time while packaging methods had no significant effect on any of the qualities.