Preservation of mango juice by freezing and canning

In this work the preservation of mango juice by freezing and canning was compared. The following results were obtained: The loss of ascorbic acid during the preparation of canned mango juice is mainly due to the processing steps other than retorting which had the least harmful effect. The retention of ascorbic acid and carotene after canning and freezing was nearly the same. Both freezing and canning caused no marked changes in the pectin content. The inactivation of the pectin methylesterase was more obvious after canning than after freezing. Reducing sugars slightly increased after freezing and canning, while the acidity and pH showed no appreciable changes. The chemical constituents except the sugars of the commercial samples were lower than those of the experimental samples. During storage, the percentage retention of ascorbic acid and carotene were lower when pasteurization was not included, and in canned samples they were higher in the experimental juice than in the market samples. Pectin content showed no changes in all cases studied. The activity of pectin methylesterase slightly decreased in frozen samples, while it was a small increase in case of canned juices. During storage the microbial count of frozen and canned samples decreased when storage progressed. The addition of water and sugar during manufacturing of commercial samples did not help to obtain a product with good storage stability. There was a significant difference between the characteristics of frozen pasteurized and non pasteurized mango juice. It seems very important to pasteurize mango juice before storage in a frozen form.     

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。     

Alternation drying and grinding (ADG) technique: A novel approach for producing ripe mango powder

The effectiveness of the alternation of drying and grinding of ripe mango for powder production was studied. Mango endosperm was dried to different moisture content and ground. There was no significant difference in ash, pectin, reducing and total sugars, starch, proteins and fat content between undried and dried mango. Bond, Kick and Rittinger grinding constants were determined. X-ray diffraction, scanning electron microscopy, differential scanning calorimetry and infrared analysis of mango granules were carried out before and after drying. Intermittent drying and grinding of ripe mango is recommended in order to increase its grinding ability. Improvement in grinding ability was characterized by the elimination of caking during grinding, the increase of the grinding yield, and the reduction of the final particle size and the energy requirement for grinding. The application of this method to ripe mango resulted in the oxidation of C-OH bonds to CO bonds in the molecular structure.     

Valuable components of raw and ripe peels from two Indian mango varieties

Mango is one of the most important tropical fruits and India ranks first in its world production. During the processing of mango, mainly for mango pulp and preparation of amchur powder, peel is a by-product. Peel forms about 20% of the whole fruit and at present it is a waste product and its disposal has become a great problem. With a view to exploit mango peel as a source of valuable components, in the present study, proximate composition, polyphenols, carotenoids, dietary fibre contents and activities of few enzymes in raw and ripe peels of two Indian mango varieties, namely, Raspuri and Badami were determined. The polyphenol contents in these peels ranged from 55 to 110 mg/g dry peel. Dietary fibre content ranged from 45% to 78% of peel and was found at a higher level in ripe peels. Similarly, carotenoid content was higher in ripe fruit peels. Vitamins C and E contents ranged from 188 to 392 and 205 to 509 μg/g dry peel, respectively; and these were found at a higher level in ripe peels. Both raw and ripe mango peels exhibited significant amount of protease, peroxidase, polyphenol oxidase, xylanase and amylase activities.     

Study of natural mango juice spoilage and microbial contamination with Penicillium expansum by high resolution H NMR spectroscopy

High resolution ¹H NMR has been applied to monitor the changes in the composition of natural mango juice subjected to spoilage and to microbial contamination with Penicillium expansum. A vast number of compounds undergoing changes upon these processes have been identified and their variations followed throughout time (132 h). Besides the formation of typical fermentation products (e.g. acetate, lactic acid, acetoin and isopropanol/2,3-butanediol) and the utilization of the major sugars (sucrose, glucose and fructose), there were changes in organic acids (e.g. decreases of quinic and shikimic acids with formation of 3,4,5-trihydroxycyclohexane acid in spoiled juice, and decreases of citric and malic acids in contaminated juice), amino acids (decreases of alanine, leucine, isoleucine and valine), and less abundant components such as oligosaccharides and aromatic compounds. The possibility of using these changes as early indicators of natural spoilage or P. expansum contamination is discussed.     

Antioxidant and tyrosinase inhibitory activity of mango seed kernel by product

The antioxidant and tyrosinase inhibitory properties of extracts of mango seed kernel (Mangifera indica L.), which is normally discarded when the fruit is processed, were studied. Extracts contained phenolic components by a high antioxidant activity, which was assessed in homogeneous solution by the 2,2-diphenyl-1-picrylhydrazyl radical and 2,2′-azinobis (3-ethylbenzothialozinesulfonic acid) radical cation-scavenging assays and in an emulsion with the ferric thiocyanate test. The extracts also possessed tyrosinase inhibitory activity. Drying conditions and extraction solvent were varied, and optimum conditions for preparation of mango seed kernel extract were found to be sun-drying with ethanol extraction at room temperature. Refluxing in acidified ethanol gave an increase in yield and the obtained extract had the highest content of total phenolics, and also was the most effective antioxidant with the highest radical-scavenging, metal-chelating and tyrosinase inhibitory activity. The extracts did not cause acute irritation of rabbit skins. Our study for the first time reveals the high total phenol content, radical-scavenging, metal-chelating and tyrosinase inhibitory activities of the extract from mango seed kernel. This extract may be suitable for use in food, cosmetic, nutraceutical and pharmaceutical applications.     

Effect of low-temperature preservation on the quality of vacuum-packaged dry-cured ham: Refrigerated boneless ham and frozen ham cuts

The effect of storage on dry-cured ham quality was studied. Sixteen vacuum-packaged boneless dry-cured hams and sixteen vacuum-packaged dry-cured ham cuts were stored in darkness under refrigeration (4±2°C; 8 months) or freezing (-18±1°C; 24 months), respectively. Instrumental colour and texture, physico-chemical and biochemical parameters, sensory profile and consumer acceptability and purchase satisfaction were measured throughout storage. The overall quality of refrigerated boneless dry-cured hams and frozen dry-cured ham cuts showed only limited changes throughout long-term storage. Significant changes involved loss of odour and flavour, increased adhesiveness and modification of hardness, the Semimembranosus muscle became tender while Biceps femoris became harder, leading to a higher textural homogeneity. In agreement with those changes, the overall acceptability assessed by a trained panel decreased throughout storage, though this was significant regarding only frozen hams. However, consumer evaluation of acceptability, as well as satisfaction with hypothetical purchasing, did not vary significantly throughout storage.     

Effect of vacuum impregnation on the phenolic content of Granny Smith and Stark Delicious frozen apple <Emphasis Type="Italic">cvv</Emphasis>

ABTS•+ test, o-diphenols (spectrophotometric) and HPLC-DAD phenolic content in vacuum impregnated apple slices from Stark Delicious and Granny Smith cvv. were studied. Vacuum impregnation (VI) was carried out in a pilot plant using an aqueous solution containing 37.9% dextrose, 15.2% sucrose, 1.0% ascorbic acid, 0.25% calcium chloride and 0.25% sodium chloride. The impregnation time was 30 min and the vacuum pressure was 100 mbar; the temperature was 25 °C during all processing steps and the solution/fruit ratio was 11:1. At the end of VI, samples were left 5 min in syrup. They were then rinsed with water, drained in a vibrating screen and quickly frozen. A significant decrease (p < 0.05) of the o-diphenol content was seen (17.84 and 12.32% of the initial content in Stark and Granny varieties, respectively). The same trend was confirmed by HPLC-DAD where reductions in total phenols were 21.57 and 26.86% in Stark and Granny, respectively. Individual phenolic compounds showed different rates of depletion, although in some cases there was no reduction. The ABTS•+ test was strongly affected by the presence of ascorbic acid (AA), which was much higher in treated samples. Sensory evaluation showed higher values of hardness, crispness, juiciness and sourness in VI Granny Smith than VI Stark delicious, with a higher retention of texture parameters in the former. Finally, sweetness was slightly higher in VI Stark. An erratum to this article can be found at     

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.     

壳聚糖对芒果炭疽病菌、蒂腐病菌的拮抗作用

以芒果炭疽病菌、蒂腐病菌为实验菌株，研究了不同pH、酸溶剂的种类对壳聚糖抗菌活性及其抗菌稳定性的影响。结果表明：壳聚糖的抑菌率随着壳聚糖浓度的提高而提高；在pH4．8和pH6．0的环境中，壳聚糖的抗菌能力较强；壳聚糖的乳酸溶液对芒果蒂腐病菌有很强的抑制力；壳聚糖连续刺激诱导40代后，芒果炭疽病菌、蒂腐病菌的EC50值均有所提高，其中以芒果球二孢霉蒂腐病菌和芒果褐色蒂腐病菌变化最显著，说明壳聚糖对其抗菌稳定性最差。     

Optimization of Maltodextrin and Tricalcium Phosphate for Producing Vacuum Dried Mango Powder

Drying of mango pulp into powder is a challenging operation, mainly due to the sticky issue of mango powder in the dryer and caking during handling and storage. To overcome the above problem, maltodextrin, MD (drying aid) and Tricalcium Phosphate, TCP (anti caking agent) were added to the mango pulp at three levels and vacuum dried. The dried powder was analysed for properties such as hygroscopicity, degree of caking, flowability and sticky point temperature. Factorial design of experiment was used to investigate the effect of MD and TCP on the mango powder properties. The amount of MD and TCP required to reduce powder stickiness and caking were optimized based on the powder properties. At the optimum amount of MD (0.527 kg per kg dry mango solid) and TCP (0.0167 kg per kg dry mango solid), the values of mango powder properties were: hygroscopicity = 6.4 %; degree of caking = 7.8%; flowability = 18.6 s; sticky point temperature = 47.4°C.     

A new solution approach for simultaneous heat and mass transfer during convective drying of mango

The present investigation is contemplated to fill a gap in analytical modelling of coupled heat and mass transfer during convective drying process. A transport model to describe the temperature and moisture evolutions of mango slab is established. The main innovation introduced in this study is represented with the procedure of temperature and moisture predictions. Mango fruit dehydration can be easily simulated with implementation of the present advanced analytical technique at different operating conditions. Moreover, the temperature and moisture history of mango slice are presented for varying values of the drying air factors counting temperature, velocity, relative humidity and initial food temperature. This work confirms that notable time can be saved without sacrificing accuracy by applying proposed model. This method is expected to be useful for fast and accurate drying simulation. The agreement between published experimental results and model predictions is remarkable and an accurate simulation of experimental drying curves is obtained.     

我国出口无蔗糖芒果蜜饯国内外食品安全标准限量分析

随着生活水平的提高和人们健康意识的增强,人们会更加注意摄入低糖低热的食品,无糖食品逐渐得到尤其女士、肥胖人士等人群喜爱。无蔗糖蜜饯不采用传统蜜饯糖渍加工工艺,不添加蔗糖,是一种新兴健康高品质的蜜饯食品。由于不含蔗糖,满足了人们特别是特殊人群对无糖蜜饯产品的需求,逐渐得到国际市场上消费者的喜爱。随着环保、健康意识的不断增强,国外"绿色技术性贸易壁垒"越来越严格,如日本的"肯定列表制度"对于蜜饯等食品的农残要求达到近乎苛求的地步,美国、欧盟等发达国家对于农药限量等食品安全限量的要求同样日趋严格,我国出口蜜饯产品因为农药残留、添加剂等食品安全不达标而被退货的例子屡见不鲜,已成为制约出口的重大质量隐患。本文通过对无蔗糖芒果蜜饯国内外食品安全标准限量比对,分析出主要贸易国家限量与我国标准的差异,指导我国出口生产企业及时作出应对措施,提升产品质量安全水平,生产出符合国际标准的无蔗糖芒果蜜饯,提高我国无蔗糖芒果蜜饯的竞争力,促进企业经济效益和社会效益增长。     

Dispersibility of freeze-dried poly(epsilon-caprolactone) nanocapsules stabilized by gelatin and the effect of freezing

A nanocapsule (NC)-gelatin suspension was freeze-dried to produce a sample of dry food. The obtained dried product was rehydrated, and the dispersibility of the nanocapsules was investigated. It was found that the prepared freeze-dried food had different dispersion characteristics at different positions in the dried bulk sample, and this heterogeneity was dependent on the cooling program used during the processing. A model mathematical calculation was carried out in order to obtain the thermal profiles of the sample during freezing. The freezing front velocity and the viscosity of the solution at/around the freezing front were estimated by using the simulated thermal profiles. The dispersibility of the prepared dry food was found to correlate with these values. This suggested that the gel network formation of NC-gelatin would be advantageous for producing excellent NC dispersion characteristics after drying. A slow cooling condition is favourable for promoting sol-gel transition in the solution. However, the large scale of ices formed during slow freezing would damage the gel networks, leading to poor dispersibility. The present work discusses key processing factors for controlling the dispersion characteristics of nanocapsules stabilized in a freeze-dried food sample.     

Stability of arsenic compounds in seafood samples during processing and storage by freezing

In this study, the stability of arsenic compounds in fresh and frozen samples of raw, boiled and fried Atlantic cod (Gadhus morhua), Atlantic salmon (Salmo salar) and blue mussel (Mytilus edulis) were examined. Results show that the total arsenic concentrations of the fresh Atlantic cod and Atlantic salmon samples were not different from the frozen samples within the same seafood type. For blue mussel, the total arsenic concentration decreased significantly after storage. Inorganic arsenic was found only in blue mussels and, importantly, no significant increase of inorganic arsenic was observed after processing or after storage by freezing. The content of tetramethylarsonium ion was generally low in all samples types, but increased significantly in all fried samples of both fresh and frozen seafood. Upon storage by freezing, the arsenobetaine content was reduced significantly, but only in the samples of blue mussels.     

Total phenolics,antioxidant activity,and functional properties of ‘Tommy Atkins’ mango peel and kernel as affected by drying methods

Mango processing produces significant amount of waste (peels and kernels) that can be utilized for the production of value-added ingredients for various food applications. Mango peel and kernel were dried using different techniques, such as freeze drying, hot air, vacuum and infrared. Freeze dried mango waste had higher antioxidant properties than those from other techniques. The ORAC values of peel and kernel varied from 418–776 and 1547–1819 μmol TE/g db. The solubility of freeze dried peel and kernel powder was the highest. The water and oil absorption index of mango waste powders ranged between 1.83–6.05 and 1.66–3.10, respectively. Freeze dried powders had the lowest bulk density values among different techniques tried. The cabinet dried waste powders can be potentially used in food products to enhance their nutritional and antioxidant properties.     

Isolation and identification of Alicyclobacillus acidocaldarius by 16S rDNA from mango juice and concentrate

In this study we investigate the spoilage of ultra high temperature UHT mango juice as well as a carbonated fruit juice blend to identify organisms contributing to the spoilage. The mango concentrate, the final product, as well as the other ingredients used during manufacturing, were tested for the presence of Alicyclobacillus by polymerase chain reaction (PCR) and sequencing analyses. Microbiological examination of the mango pureé and spoiled fruit juices, using YSG agar [yeast extract 2 g, glucose 1 g, soluble starch 2 g, pH 3.7 (adjust with 2N H₂SO₄), H₂O 1000 mL, bacto agar 15 g] incubated at 55 °C, detected sporeforming, acid dependent and thermotolerant bacteria. The hyper variable region of the 16S rDNA was amplified. The nucleotide sequence of the PCR fragments was determined using the ABI Prism 310 automated DNA sequencer and the collected sequencing data were analysed and compared with the non‐redundant database using NCBI‐BLAST. Alicyclobacillus acidocaldarius were isolated and identified by 16S rDNA gene sequences analyses. The results indicated that the mango purèe, as well as the final product of mango juice and the fruit juice blend, were positive for Alicyclobacillus. The preventative measures of low pH, pasteurization of mango juice and the subsequent use of aseptic packaging were not regarded as sufficient to prevent the outgrowth of Alicyclobacillus spoilage organisms.     

Dry-cured ham quality and acceptability as affected by the preservation system used for retail sale

Dry-cured ham cuts and slices were stored at 4 ± 2 °C for 8 months under vacuum and modified atmosphere (20% CO₂ + 80% N₂), respectively. Instrumental colour and texture, pH, non-protein nitrogen, total volatile basic nitrogen, acidity, lipid oxidation, sensory profile and consumer acceptability and purchase satisfaction were measured throughout storage. The overall quality of vacuum-packaged dry-cured ham cuts showed limited changes. Significant changes of sensory attributes involved only loss of flavour. The overall acceptability assessed by both trained and consumer panels did not decrease significantly throughout storage and the willingness to purchase remained above 50%. Conversely, modified-atmosphere-packaged ham slices had intense and extensive changes affecting sensory quality, particularly in visual appearance, flavour loss, off-flavour formation, saltiness and rancidity. Some of these changes were related to oxidation caused by low pH due to the presence of carbon dioxide in the protective atmosphere. Acceptability was significantly lower from the 4th month of storage and willingness to purchase fell below 50% at the same time.