Biological control of blue mould on apple by a strain of Candida sake under several controlled atmosphere conditions

The biocontrol potential of the yeast Candida sake (CPA-1) against Penicillium expansum decay of apples under several controlled atmosphere conditions was investigated. In a laboratory trial under different commercial cold storage conditions, increasing concentrations of C. sake improved decay control. A maximum reduction of decay was achieved at 3% O2-3% CO2 atmosphere. It amounted to a 97% lesion reduction after treatment with a suspension containing 2.4 x 10(6) CFU/ml of C. sake (CPA-1). In a semi-commercial trial at 1 degree C with wounded fruits, the reduction in decay diameter caused by C. sake exceeded 80% after 60 days at 21% O2 and 60% after 120 days of storage under controlled atmosphere conditions. For seven controlled atmosphere conditions studied, a significant influence by C. sake on the P. expansum decay was observed, and the lesion size was reduced more than 70% by C. sake at 10(7) CFU/ml. The populations of C. sake (CPA-1) on the apple surface followed the same pattern under all controlled atmosphere conditions studied. They decreased 4-10-fold during the first 2 weeks, followed by an increase to the initial level after 45 days, and thereafter the count remained constant for the period of 90 days examined. This indicated the capacity of C. sake (CPA-1) to colonize the surface of apples under various storage conditions. The ability to colonize was even higher in apple wounds.     

Biological control of postharvest pear diseases using a bacterium, Pantoea agglomerans CPA-2.

Epiphytic microorganisms isolated from the fruits and leaf surfaces of apples and pears were screened for antagonistic activity against Penicillium expansum on pears. From 247 microorganisms tested for antagonistic properties against P. expansum, a bacterium strain identified as Pantoea agglomerans (CPA-2) was selected. This bacterium was very effective against Botrytis cinerea, P. expansum and Rhizopus stolonifer. Complete control at the three tested concentrations (2 x 10(7), 8 x 10(7) and 1 x 10(8) CFU ml(-1)) was obtained on wounded pears inoculated with 10(3), 10(4) and 10(5) conidia ml(-1) of P. expansum and R. stolonifer. At 8 x 10(7) CFU ml(-1), Pan. agglomerans reduced B. cinerea decay by more than 80% at the three concentrations of the pathogen. In over 3 years of experiments in semicommercial trials, Pan. agglomerans provided excellent control against B. cinerea and P. expansum under cold storage, either in air or in low oxygen atmospheres. Equal control was obtained with Pan. agglomerans at 8 x 10(7) CFU ml(-1), as with the fungicide imazalil at commercial doses, against both pathogens. Pan. agglomerans grew well inside wounds on pears at both room and cold temperatures and under modified atmospheres. In contrast, it grew poorly on the surface of intact fruit.     

Effect of biocontrol agents Candida sake and Pantoea agglomerans on Penicillium expansum growth and patulin accumulation in apples

Penicillium expansum is the major responsible of fruit pome decaying in cold storage. Apples spoiled by P. expansum are expected to contain patulin, a mycotoxin which is proven to affect human health. The use of chemicals is the most common procedure to prevent rots in postharvest but legislation is becoming more and more restrictive. The use of biocontrol agents (BCA) as an alternative tool is currently being proposed. The aim of this study was to evaluate the effect of two BCA (Candida sake CPA-2 and Pantoea agglomerans CPA-1) on P. expansum growth and patulin accumulation in cold storage and further deck (ambient) storage. Wounded apples were inoculated with a cell suspension of either C. sake or P. agglomerans and with a P. expansum conidial suspension. Apples were cold stored at 1 degrees C until lesion diameter reached 2 or 4 cm. Half the apples of each treatment were further stored at 20 degrees C for three days before patulin analyses. Both BCA tested controlled blue rot and patulin accumulation during cold storage. The control of P. expansum growth was enhanced in C. sake treated apples. On the other side, control of patulin accumulation in P. agglomerans treated apples seemed to be more efficient. BCA treatment could not control blue rot and patulin accumulation during further storage at room temperature and in some cases, an increase in P. expansum aggressiveness was observed.     

High Vacuum Flame Sterilized Fruits: Storage Study on Sliced Clingstone Peaches, Sliced Bartlett Pears, and Diced Fruit

Slices of four major commercial clingstone peach varieties, slices of Bartlett pears from major growing areas, and mixtures of diced peaches and pears were successfully vacuum packed without the conventional covering syrup or water. For selected packs, the fruits were sweetened to the desired cutout °Brix value with concentrated syrup. The high vacuum flame sterilized packs (HVFS) required only 7.5 min total heating for pear and peach slices and 5.5 min for diced fruit to achieve biological stability. Because of the minimal process, all HVFS fruits retained more of the original flavor attributes and texture of the fresh fruit through 18 months storage than did the conventional packs. Omission of the covering liquid, combined with the necessary blanching treatment, allowed packing of 1/3 more fruit into a standard size can.     

PRODUCT DEVELOPMENT AND NUTRACEUTICAL ANALYSIS TO ENHANCE THE VALUE OF DRIED FRUIT

ABSTRACT

Value‐added fruit products suitable for production by small‐scale farmers and processors were developed and evaluated. Apples, blueberries, peaches and strawberries from local growers were processed into a dried fruit product. The total phenolics, total anthocyanins and oxygen radical absorbing capacity (ORAC) were determined. Drying the fruit concentrated total phenolics, total anthocyanins and ORAC levels as compared to fresh fruit. The nutraceutical components of the blueberries, peaches and strawberries of the local dried fruit were higher than those of commercial dried fruit purchased at a natural food store. The dried fruit from both the local and commercial fruits was used to create a fruit pie filling for consumer evaluation. Consumer acceptance of fruit pie filling from dried fruit grown locally and dried commercial fruits was evaluated using a 9‐point verbal hedonic scale and a 5‐point Just About Right scale. In terms of consumer evaluation, the pie fillings made from local dried fruits were either better or at parity with those from commercial products. In addition to the nutraceutical benefits, the pie fillings were consumer acceptable products that could represent an avenue for small‐scale farmers to add value to surplus fruit.

PRACTICAL APPLICATIONS

Complete utilization of fruit crops is a key component to the success of small farm operations. Excess fruit crops can be dried (or processed in other manners) and used to create many value‐added products. Increased consumer awareness of healthy food products provides a niche market for these fruit products. In this research, the nutraceutical benefits of fresh and dried apples, blueberries, peaches and strawberries were investigated and the consumer overall acceptance of a pie filling produced from these dried fruit was shown.

     

我国天然果酒的研究与开发

果酒是以果品为原料经发酵酿制而成的低度饮料酒,酒度一般在12％Vol左右,果酒具有低酒度、高营养、益脑健身等特点。我国用于果酒开发的天然植物资源极为丰富,以果实形态结构和利用特征大致分为浆果、仁果、核果、柑果、坚果、亚热带和热带果实6类;果酒酿造的基本工艺分为4个阶段：发酵前处理获取果汁;果汁的调整;果汁前发酵、后发酵及陈酿;灭菌、包装。随原料生产基地建设的加强和丰富的原料提供,新技术、新工艺的应用,酒类消费市场的改善,果酒品种的多样化,果酒国家标准的制定、执行,生产工艺、设备的发展,我国果酒工业的产业规模化、现代化发展将得以实现。     

猕猴桃无籽果羹加工工艺研究

以猕猴桃鲜果为原料,进行猕猴桃无籽果羹加工工艺与配方优化的研究,结果表明:以果实硬度大于9.0kg/cm2的鲜果经机械去皮、挖芯、破碎工艺制得的果泥47.2%,熟软果实榨汁得到的无籽果汁41.3%,复配稳定剂0.20%(0.08%卡拉胶+0.04%结冷胶+0.08%CMC),果葡糖浆11.2%的最优配方调配的猕猴桃无籽果羹产品,经常压90～95℃温度杀菌20min处理后保质期为6个月。     

2019年重庆市水果类监督抽检情况分析

目的 研究2019年重庆市水果类监督抽检结果, 分析新鲜水果类食品存在的主要食品安全风险。 方法 整理汇总了重庆市市场监督管理局2019年发布的44个食品安全抽检信息通告, 提取食用农产品中新鲜水果类的数据, 对不合格样品进行分析。结果 2019年重庆市共抽检了3785批次水果类食用农产品, 包括了29个水果品种。不合格数37批次, 不合格率为0.98%, 包含柑、橘,香蕉,苹果。柑、橘不合格率为2.08%, 不合格项目是丙溴磷; 香蕉不合格率为15.98%, 不合格项目是吡唑醚菌酯; 苹果不合格率为0.11%, 不合格项目是敌敌畏。其余水果品种未发现不合格样品。结论 2019年重庆市水果类食品安全总体形势良好, 但应警惕柑、橘水果中的丙溴磷和香蕉中的吡唑醚菌酯的违规使用。     

Influence of diluent and sample processing methods on the recovery of the biocontrol agent Pantoea agglomerans CPA-2 from different fruit surfaces

Determining the populations of biocontrol agents applied as a postharvest treatment on fruit surfaces is fundamental to the assessment of the microorganisms' ability to colonise and persist on fruit. To obtain maximum recovery, we must develop a methodology that involves both diluent and processing methods and that does not affect the viability of the microorganisms. The effect of diluent composition was evaluated using three diluents: phosphate buffer, peptone saline and buffered peptone saline. An additional study was performed to compare three processing methods (shaking plus sonication, stomaching and shaking plus centrifugation) on the recovery efficiency of Pantoea agglomerans strain CPA-2 from apples, oranges, nectarines and peaches treated with this biocontrol agent. Overall, slight differences occurred among diluents, although the phosphate buffer maintained the most ideal pH for CPA-2 growth (between 5.2 and 6.2). Stomaching, using the phosphate buffer as diluent, was the best procedure for recovering and enumerating the biocontrol agent; this fact suggested that no lethal effects from naturally occurring antimicrobial compounds present on the fruit skins and/or produced when the tissues were disrupted affected the recovery of the CPA-2 cells, regardless of fruit type. The growth pattern of CPA-2 on fruits maintained at 20°C and under cold conditions was similar to that obtained in previous studies, which confirms the excellent adaptation of this strain to conditions commonly used for fruit storage.     

Mould and yeast flora in fresh berries, grapes and citrus fruits

Fresh fruits are prone to fungal contamination in the field, during harvest, transport, marketing, and with the consumer. It is important to identify fungal contaminants in fresh fruits because some moulds can grow and produce mycotoxins on these commodities while certain yeasts and moulds can cause infections or allergies. In this study, 251 fresh fruit samples including several varieties of grapes, strawberries, blueberries, raspberries, blackberries, and various citrus fruits were surface-disinfected, incubated at room temperature for up to 14 days without supplemental media, and subsequently examined for mould and yeast growth. The level of contamination (percent of contaminated items/sample) varied depending on the type of fruit. All raspberry and blackberry samples were contaminated at levels ranging from 33% to 100%, whereas 95% of the blueberry samples supported mould growth at levels between 10% and 100% of the tested berries, and 97% of strawberry samples showed fungal growth on 33-100% of tested berries. The most common moulds isolated from these commodities were Botrytis cinerea, Rhizopus (in strawberries), Alternaria, Penicillium, Cladosporium and Fusarium followed by yeasts, Trichoderma and Aureobasidium. Thirty-five percent of the grape samples tested were contaminated and supported fungal growth; the levels of contamination ranged from 9% to 80%. The most common fungi spoiling grapes were Alternaria, B. cinerea and Cladosporium. Eighty-three percent of the citrus fruit samples showed fungal growth at levels ranging from 25% to 100% of tested fruits. The most common fungi in citrus fruits were Alternaria, Cladosporium, Penicillium, Fusarium and yeasts. Less common were Trichoderma, Geotrichum and Rhizopus.     

Comparative study on disappearance trends of captan and trifloxystrobin residues on fruit and apple tree leaves using internal normalisation method

Supervised field trials were carried out in a commercial orchard in 2011. The purpose of the study was to assess the usefulness of the comparative method to examine the mechanism of disappearance of pesticide residues. Captan and trifloxystrobin residues were determined with the use of gas chromatograph equipped with a micro-electron capture detector. Disappearance trends of captan and trifloxystrobin residues in fruit and leaves were estimated using the method of internal normalisation, and based on that, the courses of concentration changes of these substances on fruit and leaves and the amount of these substances in one apple were established. The initial deposits of trifloxystrobin on leaves and fruits dropped by 50% within 8 and 4 days after treatment, respectively, in both varieties, whereas captan residues dropped by 50% within 29 days in leaves and 7 days in apples of the Olive Yellow varieties.     

Control of foodborne pathogens on fresh-cut fruit by a novel strain of Pseudomonas graminis

The consumption of fresh-cut fruit has substantially risen over the last few years, leading to an increase in the number of outbreaks associated with fruit. Moreover, consumers are currently demanding wholesome, fresh-like, safe foods without added chemicals. As a response, the aim of this study was to determine if the naturally occurring microorganisms on fruit are “competitive with” or “antagonistic to” potentially encountered pathogens. Of the 97 and 107 isolates tested by co-inoculation with Escherichia coli O157:H7, Salmonella and Listeria innocua on fresh-cut apple and peach, respectively, and stored at 20 °C, seven showed a strong antagonistic capacity (more than 1-log unit reduction). One of the isolates, CPA-7, achieved the best reduction values (from 2.8 to 5.9-log units) and was the only isolate able to inhibit E. coli O157:H7 at refrigeration temperatures on both fruits. Therefore, CPA-7 was selected for further assays. Dose-response assays showed that CPA-7 should be present in at least the same amount as the pathogen to adequately reduce the numbers of the pathogen. From the results obtained in in vitro assays, competition seemed to be CPA-7's mode of action against E. coli O157:H7. The CPA-7 strain was identified as Pseudomonas graminis. Thus, the results support the potential use of CPA-7 as a bioprotective agent against foodborne pathogens in minimally processed fruit.     

Variation in the carotenoid composition of acerola and its processed products

Acerola is now commercially produced and processed in Brazil. Known for its very high vitamin C content, this fruit is also a good source of β‐carotene. The present study was carried out to verify variation in the carotenoid composition along the food chain. Neoxanthin, violaxanthin, lutein, β‐cryptoxanthin, α‐carotene and β‐carotene were found in the acerola fruit. β‐Carotene predominated with mean concentrations of 12.4 and 38.1 µg g^?1 in the ripe fruit, 8.8 and 30.1 µg g^?1 in the peeled ripe fruit and 5.4 and 12.0 µg g^?1 in the partially ripe fruit of an undefined variety taken from home gardens and the commercial cultivar Olivier, respectively. Aside from β‐carotene, β‐cryptoxanthin increased significantly in both garden and commercial fruits and violaxanthin in the latter fruits during ripening. Peeling reduced β‐carotene in both garden and commercial lots, violaxanthin decreased in the commercial fruits, and the other carotenoids remained virtually unchanged. Four brands of frozen pulp and three brands of processed juice had variable and markedly lower carotenoid levels than those of the fresh fruit, indicating that the processing should be improved. Copyright © 2006 Society of Chemical Industry     

Infection capacities in the orange-pathogen relationship: compatible (Penicillium digitatum) and incompatible (Penicillium expansum) interactions

Penicillium digitatum and Penicillium expansum are the most devastating pathogens of citrus and pome fruits, respectively. Whereas P. digitatum is a very specific pathogen that only infects Citrus fruits, P. expansum has a broader host range but has not been reported to be infectious in Citrus. To determine the responses of fruits and the infection capacities of both moulds, two varieties of oranges at different maturity stages, different inoculum concentrations and two different storage temperatures were studied. In compatible interactions, no significant differences in rot dynamics among harvests were found with a 10⁷ conidia mL⁻¹ inoculum concentration at both temperatures tested (20 °C and 4 °C). However, at other inoculum concentrations, significant differences in rot dynamics were found, especially in immature fruits. Incompatible interactions showed that P. expansum could infect oranges at commercial maturity in both tested varieties. Decay incidence and severity were higher at 4 °C than at 20 °C. In addition to infection capacity studies, histochemical tests were performed to detect wound-healing compounds for both pathogens. A positive reaction for lignin was detected for both pathogens in immature oranges over a short period (48 h). In all cases, no reactions were found in control samples. Our results indicate that pathogen concentration, host maturity and storage temperature can play important roles in the defence mechanisms of fruit. Furthermore, to our knowledge, this is the first work that demonstrates that P. expansum can infect oranges under favourable conditions.     

鲜切猕猴桃片常温液藏及加工果脯关键工艺研究

研究了常温下液藏鲜切猕猴桃片的保鲜液最佳配方与以其为原料加工果脯的脱盐、上色、糖制等关键工艺条件。结果表明:采用10%食盐、0.07%氯化钙、0.1%蔗糖酯、0.12%山梨酸钾的保鲜溶液浸泡猕猴桃果片,贮藏效果较好,贮藏期可达6～12个月;采用水料比为2:1的洁净水浸泡果片3h进行脱盐,用0.3%叶绿素铜钠盐、0.2%氯化锌上色,糖渍5h后熬煮至终点,果片饱满度及口感俱佳。     

Influence of processing and storage on the antioxidant activity of apple derivatives

The antioxidant activity of seven apple varieties was determined on fresh fruits and processed products (dried fruits and purees) and during storage. The antioxidant activity of apples correlated with the total phenol concentration but not with ascorbic acid concentration. Apple derivatives showed a lower antioxidant activity than the counterparts of the fresh fruits and the occurrence of browning phenomena during processing resulted in lower antioxidant activity. Dried fruits showed higher antioxidant activity per gram of dried matter than fruit purees probably because of the lower total thermal effect of processing. The antioxidant activity of all products increased within the first month of storage, and then declined. The extent of early increase was related to the polyphenol content of the fruit. Packaging conditions further influenced the antioxidant activity increase during storage possibly by affecting the oxygen availability.     

Radiation preservation of foods of plant origin. Part V. Temperate fruits: pome fruits, stone fruits, and berries

The current status of research on the application of ionizing radiation for improving the storage of temperate fruits, i.e., apple, pear, peach, nectarine, apricot, cherry, plum, strawberry, bilberry, cranberry, raspberry, and black currant, is reviewed. Changes in fruit metabolism, chemical composition, texture, and organoleptic quality attributes are discussed with reference to the irradiation dose. The feasibility of using radiation either alone or in conjunction with heat treatment, refrigeration, and controlled atmospheres (CA) for the control of storage decay caused by fungal pathogens is considered. Areas of further research are suggested before irradiation could be considered for practical application in some of these temperate fruits. The recent trends in the possible use of irradiation for disinfestation of certain pome and stone fruits and the prospects for the commercial utilization of irradiation for improving the market life of strawberries are discussed.     

Significance of osmotic temperature treatment and storage time on physical and chemical properties of a strawberry-gel product

BACKGROUND: The development of fruit‐based foods that maintain the nutritional and sensory properties of fresh fruit may help to stimulate fruit consumption by consumers. The possibility of formulating a fruit‐gel product with osmodehydrated fruit and the reused osmotic solution (OS) obtained from the dehydration step has been demonstrated. However, the conditions of the osmotic process can significantly affect the properties of the obtained product. In this work an osmotic process at 22 °C for 6 h and at 30 °C for 3 h was employed to formulate a strawberry‐gel product. RESULTS: Significant losses of ascorbic and citric acids and anthocyanins were observed and some relevant volatile compounds of the strawberry aroma profile were developed during the osmotic process. Changes in all analysed parameters occurred mainly during the first 2 days of storage. The flux of anthocyanins from the fruit to the gel gave an attractive appearance to the formulated product. These changes were more marked for samples obtained at 30 °C. CONCLUSION: Osmotic treatment at 30 °C was more suitable for formulation of the product, because the presence of nutritional/functional compounds in the OS, and consequently in the gel matrix, was higher and the aroma and colour were more stable and homogeneous during storage. Copyright © 2011 Society of Chemical Industry     

COMPARATIVE RADIATION DOSE MAPPING OF SINGLE FRUIT TYPE AND MIXED-FRUIT BOXES FOR EXPORT FROM HAWAII

A generic radiation quarantine treatment of 400 Gy for insect pests infesting fresh fruit and vegetable and other horticultural commodities was recently approved in the U.S.A. Dose-mapping studies were conducted to compare dose variation during radiation treatment at 400 Gy of a single-fruit type and of mixed fruits packed in boxes. The tests included papaya, mango, banana, rambutan, longan, dragon fruit and various combinations of these tropical fruits. When radiation was applied to a single box containing one type of fruit or a mixture of two or three fruit types, measured doses were sometimes higher in the mixture. Irradiation of a simulated commercial load of 12 boxes resulted in no significant difference between single-fruit boxes and mixed-fruit boxes. In all experiments, the technical objectives of radiation treatment were met, meaning that all resulting doses fell between the minimum required dose of 400 Gy and the maximum allowable dose of 1,000 Gy.

PRACTICAL APPLICATION

Quarantine treatment protocols to disinfest fresh agricultural commodities of quarantine insect pests are traditionally developed for single commodities. No postharvest quarantine treatment has ever been approved for mixed fresh commodities. The information contained herein using a generic radiation dose will be submitted to regulatory authorities to gain approval for the first disinfestation treatment for mixed fresh commodities. This could lead to export approvals for value-added mixed-fruit gift boxes or other products which would diversify revenue for the tropical fruit industry.     

Chemical profiling of volatile compounds of various home‐made fruit spirits using headspace solid‐phase microextraction

Fruit spirits are typical alcoholic beverages in the Moravian region of the Czech Republic. The aim of this work was to find differences in chemical composition among volatile profiles of spirits produced from various kinds of fruits. Twenty‐four samples of seven kinds of fruit spirits (plum, apple, pear, cherry, mirabelle, apricot and raspberry spirits) were analysed for examination of their volatile profiles. The most abundant family of compounds was esters, particularly ethyl esters. Sesquiterpenes proved to be a significant group of volatile substances by observing the differences between pome and stone fruit spirits [by relative higher content of (E ,E )‐α‐farnesene and by presence of α‐zingiberene and (E )‐α‐bisabolene in volatile profiles of pome fruit spirits]. Only in stone fruit spirits were propyl decanoate and ethyl salicylate found. Some other compounds were observed as being characteristic for individual kinds of analysed fruit spirits, e.g. γ‐decalactone for apricot spirits, (E )‐β‐farnesene for apple spirits, (Z )‐9‐tetradecen‐1‐ol for mirabelle spirits or some apocarotenoids for raspberry spirits. This work could potentially be the basis for checking the fruit origin of these distillates, or a partial manual as to how to differentiate individual kinds of pome‐fruit spirits (pear and apple spirits) or stone‐fruit spirits (plum, mirabelle, apricot spirits). Copyright © 2017 The Institute of Brewing & Distilling