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Fresh-cut broccoli florets shelf-life as affected by packaging film mass transport properties
Abstract
In this work, the influence of packaging film mass transport properties on the quality loss of fresh-cut broccoli florets is addressed. The work was divided into two subsequent experimental steps; first, the selection of potential packaging films was carried out by monitoring the headspace gas concentrations in package of broccoli. Then, the mass transport properties of some previous selected films were assessed on product shelf-life. To this aim, unpackaged fresh-cut broccoli and intact broccoli wrapped in polyvinyl chloride were used as controls. Headspace gas concentration, mass loss, sensorial quality and spoilage microbial growth were monitored. The micro-perforated films were the most effective in reducing mass loss, wilting and maintaining sensory quality for a longer period. In particular, the micro-perforated film that had the lowest OTR value showed the best performance in prolonging of the product shelf-life if compared to either control samples and fresh-cut broccoli packaged in the non-perforated film. The results highlighted that an approximately 50% shelf-life increase of fresh-cut florets broccoli compared to whole broccoli, and of about 30% respect to the unpackaged fresh-cut produce was obtained.
... Florets packaged in CAD30 presented intermediate levels of O 2 and CO 2 (16.1 ± 0.33 kPa and 3.3 ± 0.13 kPa, respectively, at day 7). Similar gas composition evolutions were reported by Lucera et al. (2011) [26] for broccoli florets packaged in polypropylene micro-perforated films, who observed a slow decrease in O 2 at the beginning of the storage (5 • C) and an equilibrium value of about 16 kPa. ...
... Florets packaged in CAD30 presented intermediate levels of O 2 and CO 2 (16.1 ± 0.33 kPa and 3.3 ± 0.13 kPa, respectively, at day 7). Similar gas composition evolutions were reported by Lucera et al. (2011) [26] for broccoli florets packaged in polypropylene micro-perforated films, who observed a slow decrease in O 2 at the beginning of the storage (5 • C) and an equilibrium value of about 16 kPa. ...
... However, broccolis transferred to 7 • C tended to have greater mass loss compared to those held at 2 • C. Films with different levels of perforation also had no significant effect on the mass loss of broccoli florets, although CAD45 and CAD15 tended to have the lowest and highest mass loss throughout storage, respectively. Our results agree with Lucera et al. (2011) [26], who reported a weight loss of less than 3% for broccoli florets stored for 24 d at 5 • C, regardless of the number of film micro-holes. In all conditions of this study, mass loss was less than the maximum limit of marketability (6%) and was not a factor limiting the shelf-life of broccoli florets [21]. ...
Fresh-cut broccoli is a highly demanded product due to its convenience and high content of bioactive compounds. Unfortunately, this product shows rapid senescence and anoxia generation problems, especially when storage temperature varies. Therefore, perforation-mediated modified atmosphere packaging (PM-MAP) of broccoli florets, in different temperature scenarios, was studied. Polypropylene films with different levels of laser perforation were evaluated. After packaging, florets were stored at two temperatures: 2 °C, and 2 °C + 7 °C (during 2 d before sampling). PM-MAP slightly modified the internal composition of O2 (14–20 kPa) and CO2 (0.9–5 kPa) and allowed us to preserve the external quality and bioactive compounds of broccoli florets throughout 21 d, even at 7 °C. The generation of anoxia was avoided at both temperatures. PM-MAP kept broccoli mass loss below 0.5% and preserved its sensory quality. The perforation level affected evolution of firmness and glucosinolate content, especially with increasing temperature. Broccolis packaged in the film with fewer perforations showed higher firmness (0.73 ± 0.09 N/mm) and total glucosinolate content (10 ± 0.3 mg/g) compared to broccolis packaged in films with higher perforations (0.59 ± 0.05 N/mm and 8.60 ± 0.2 mg/g). Therefore, the perforation level should be taken into account in the design of packaging for fresh-cut products.
... As will be discussed later, this is linked to the deterioration of the organoleptic quality of the packaged product. As noted by Lucera et al. (2011), the optimal MAP design for broccoli raab should aim for O 2 and CO 2 levels of approximately 10%, as achieved in our study using PP/PA MF-aMAP. ...
... Similar results were noted by Cefola et al. (2016), who observed approximately 18% weight loss in air-stored broccoli raab, significantly higher than that of samples packaged using polypropylene/polyethylene terephthalate (PP/PET) and microperforated polypropylene/polyamide (PP/PA MF), leading to greater quality loss. Lucera et al. (2011) confirmed this, showing losses of up to 40% for air-stored samples compared to 3% for packed "cima di rapa". The use of biodegradable films with high water vapor transmission rate caused a very high percentage of weight loss, highlighting the importance of selecting an appropriate plastic material . ...
... kPa after the same period. Nevertheless, Lucera et al. (2011b) reported that O 2 concentrations of fresh-cut broccoli florets packaging under MAP decreased rapidly to zero during the first 40 h of storage. Moreover, they showed that observed decrease was different and it depended on the film applied. ...
... Nevertheless, the counts at the end of storage in both modified atmosphere-and vacuum-packaged samples were kept below 6 log cfu g À1 indicating that the concentrations of O 2 in the packages were effective in controlling the growth of mesophilic aerobic bacteria. Similar results were obtained in a studies carried out with fresh-cut green beans and fresh-cut broccoli florets packaged under MAP (Lucera et al., 2011a(Lucera et al., , 2011b. Mesophilic aerobic bacteria counts of all studied fresh-cut calc¸ots not exceeded the recommended limit of 8 log cfu g À1 proposed by CNERNA-CNRS (1996). ...
Calçots are the immature floral stems of the second-year onion ( Allium cepa L.) resprouts. Modified atmosphere packaging or vacuum packaging are suitable alternatives to preserve fresh-cut vegetables. The objective of this study was to evaluate the effect of postharvest storage time of raw vegetable stored under controlled atmosphere and used packaging system after minimal processing on the quality of fresh-cut calçots. Calçots used for minimal processing were stored under 1.0 kPa O 2 + 2.0 kPa CO 2 at 1 ℃ for 30 and 60 days. Fresh-cut calçots were packaged using passive modified atmosphere packaging or vacuum packaging and were stored at 4 ℃ for 15 days. Calçots stored under controlled atmosphere for 30 days presented better retention of quality and in turn, being more suitable for minimally processing. Vacuum packaging preserved the physicochemical quality of fresh-cut calçots better after 15 days. Mesophilic aerobic counts were also higher in fresh-cut calçots stored under modified atmosphere packaging, but all counts were below the recommended limits during and at the end of their shelf-life (15 days). The most suitable conservation strategy might be to store whole calçots under controlled atmosphere for 30 days and after minimally processing, packaged under vacuum in order to extend the shelf-life of fresh-cut calçots.
... Ben-Yehoshua (1985) reported that packaging of fruits in low-density polyethylene (PE) bags delays ripening and softening and hence improves marketability. Perforated films are commonly used for MAP of fresh fruits and vegetables to control respiratory activity and the transfer of gases through the polymeric matrix (Lucera et al. 2011). Temperature is generally the most common variable that affects stored fruits and vegetables and, along with other climatic factors, causes various metabolic changes in fruits after harvest. ...
... Increasing the perforation size significantly (p B 0.05) decreased the percentage of CO 2 in the package, whereas that of O 2 was significantly increased. Perforated films are commonly used for MAP of fruits and vegetables to control respiratory activity and the transfer of gases through the polymeric matrix (Lucera et al. 2011). Various studies have reported the effects of perforations on the transport of water vapor and gases to achieve the desired modified atmosphere within a package of fresh horticultural produce (González et al. 2008). ...
The effects of modified atmosphere packaging (MAP) on various physicochemical quality attributes of fresh Barhi dates at the Khalal (yellow) stage were studied. Polypropylene (PP) and polyethylene (PE) plastic with varied perforation sizes (0, 50, 100 and 150 µm) were evaluated for storage of date fruits at temperatures of 1, 5, 15 and 25 °C up to 45 days. MAP showed significant effects on fruit quality. PP date packages perforated with 150-µm perforations and stored at 5 °C had the lowest acidity and microbial load. Dates packed in PE exhibited higher pectin methylesterase (PME) and polyphenol oxidase (PPO) activities than dates packed in PP. Dates stored in nonperforated packages had the highest PME, PPO and invertase activities. The maximum fructose and glucose contents were observed in PP-packaged dates stored at 15 °C. Analysis of the interactions of several MAP variables revealed temperature as the major variable controlling the quality of dates. The findings showed that MAP can be effectively employed to preserve the quality and improve the shelf life of Barhi dates using PP with 150-µm perforations as the packaging material during storage for 2 weeks at 5 °C.
... However, it is an extremely perishable vegetable due to its high respiration rate. Moreover, when broccoli is processed to be marketed as a ready-to-eat fresh vegetable, unit operations exerted such as washing, cutting and packaging promote a faster physiological deterioration and hastened biochemical changes (Lucera et al., 2011), impacting on product's sensory and nutritional quality. ...
... Although recommended atmospheric levels for broccoli are 1-2 kPa O 2 and 5-10 kPa CO 2 at low temperatures (Lucera E. Paulsen et al. Postharvest Biology and Technology 138 (2018) 125-133 et al., 2011), passive modified atmosphere packaging of broccoli is often designed to maintain both O 2 and CO 2 at about 10 kPa in order to avoid anaerobiosis in case of temperature fluctuations (Lucera et al., 2011). Considering these reference values, broccoli florets packaged in perforated PP bags should be kept as close as possible to 4°C in order to reach 10 kPa O 2 and 10 kPa CO 2 atmospheric composition. ...
Ready-to-eat fruit and vegetables comprise a group of increasingly demanded value-added products. Broccoli is a highly perishable vegetable with unique nutritional characteristics. Development of minimally processed broccoli products demands varietal-specific knowledge as to which are the packaging conditions that preserve quality throughout shelf life. ‘Legacy’ cultivar broccoli florets were washed, disinfected, packaged in polypropylene and stored at 4, 8 and 15 °C for 21 d. Weight loss, internal atmosphere composition, respiration rate, color, texture, glucosinolate content, antioxidant capacity (AOC) and sensory attributes were evaluated throughout storage time. Results showed that 4 °C helped preserve sensory quality, texture, total glucosinolate content and AOC for 21 d. Temperature fluctuations reaching 15 °C resulted in loss of total glucosinolate content and unacceptable sensory quality. MAP helped mitigate temperature effects, especially at 8 °C. MAP is therefore an appropriate technology which can be applied to extend the shelf-life of ready-to-eat broccoli florets.
... The sodium hypochlorite-treated (T 4 ) fruits had a higher oxygen concentration (13.83%), whereas the UV-C-treated packs had a lower carbon dioxide (1.57%) concentration inside the packs. This phenomenon may be attributed to the gas composition achieved in the headspace inside the package, which is influenced by the interaction between the film's permeability and the respiratory activity of the produce (Lucera et al., 2011). The total soluble solids (TSS) in minimally processed muskmelon fruits decreased gradually with storage duration, irrespective of the treatments the lowest reduction in TSS content was recorded in treatment T 3 (11.23°B) ...
... The loss of quality is mainly due to surface dehydration and loss of characteristic coloration, loss of stem firmness, and the development of odors and rot. 5 Among the compounds present in broccoli, kale, and cauliflower, glucosinolates stand out, as they are found only in this genus, and are responsible for the characteristic odor of these vegetables. These compounds are chemically characterized by a sulfur group attached to ⊎-D-thioglucose and a variable side chain derived from amino acids. ...
BACKGROUND
Broccoli, kale, and cauliflower contain phenolic compounds and glucosinolates, which have several biological effects on the body. However, because they are thermolabile, many of these substances are lost in the cooking process. Electrospinning encapsulation, using zein as a preservative wall material, can expand the applications of the compounds in the food and pharmaceutical industries. The objective of this research was to characterize broccoli, kale, and cauliflower extracts and encapsulate them with the electrospinning technique using zein.
RESULTS
Broccoli, kale, and cauliflower extracts contain five phenolic compounds and three glucosinolates. Fibers from broccoli, kale, and cauliflower showed high encapsulation efficiency, good thermal stability, and nanometric size, especially those containing extract and zein in proportions of up to 35:65.
CONCLUSION
Fibers from broccoli, kale, and cauliflower containing extract and zein in proportions of up to 35:65 have the potential for effective nutraceutical application for the control of non‐communicable chronic diseases or application in food packaging. © 2022 Society of Chemical Industry.
... 19 There are two main strategies to control IPRH: one is the use of micro-perforate films, 20,21 and the other is the use of inpackage water-absorbing compounds such as calcium chloride 22 or sorbitol. 23,24 13.6 App and software to calculate psychrometric parameters Although you can still find Windows desktop applications, with the rise of mobile applications, numerous apps have emerged, both for the Android operating system and for IOS to calculate psychrometric parameters. The most important apps in terms of relevance are presented in Table 13.1. ...
Psychrometry deals with the properties and behavior of gas/vapor mixture. The most commonly studied system is humid air. Humid air is also the most important gas/vapor mixture used in the food processing industry. In this chapter, different properties of humid air are revised considering their analytical expressions and practical meaning. Psychrometric charts are simple graphical methods used to represent and predict the humid air properties. Different psychrometric charts are presented and the use of these diagrams to represent humid air transformations is explained. Also, current software and apps available to calculate and predict psychrometric parameters are presented. The main applications of psychrometry in the food industry include food drying, postharvest operation of fruits and vegetables and grain storage with aerating storage. A brief explanation about these fields of applications is included in this chapter. Finally, instrumentation for air properties measurement is revised and the most recent advances in humidity sensors are presented.
... While the issues with plastic packaging waste management are a clear problem and need to be resolved, it is important to consider the benefits of plastic packaging for food preservation, sanitation and reduced global warming versus alternative materials. Plastic packaging plays an important role in the safe shelf life extension of fresh fruits and vegetables such as broccoli, 15 mangos, 16 bananas, 17 and many others. 18 Fresh proteins such as poultry, 19 beef, and fish 20 also benefit greatly from plastic packaging. ...
Plastic packaging has gained an increasing amount of attention in all aspects of society. Over the past several decades, plastics became the material of choice due to their excellent properties, performance, and economics, but the end of life of plastics is not well managed. This has led to plastic waste in our environment, especially the oceans, rivers, and estuaries, driving legislative, industrial, and voluntary initiatives to make the necessary pivot to circularity. While the plastics recycling industry has made many advances in its relatively short life, there are still many technical and societal hurdles to be overcome. The goal of this work is not to provide a complete review of recycling as it pertains to circularity, but rather to highlight the technical gaps that need to be collaboratively addressed by the entire plastics community to achieve circularity. Each stage along the path, from design of packaging and materials of construction to sortation, recycling, and reprocessing are ripe for innovation. The most relevant issues are introduced to provide a starting point for research across all fields of polymer science to aid in reducing the environmental impact of plastic packaging waste.
... PE and PP non-perforated films maintained high CO 2 and low O 2 inside the pack compared to their counterparts with perforation. This might be due to the headspace conditions/gas composition achieved in the package depending on the interactions between the respiratory activity of the packaged produce and gas transfer through the polymeric matrix and micro-perforations (Lucera et al. 2011) [9] . The exception is non-perforated PD-961 film which maintained significantly low CO 2 and high O 2 . ...
... Lv et al. reported the presence of hydrocarbons, esters, alcohols, sulfides, acids and other compounds in the headspace of broccoli employing Head-Space Solid-Phase Microextraction-Gas Chromatography-Mass Spec-trometry (HS-SPME-GCMS) [12]. Over the past few years, people have been using different quality validation methods for assessing the quality of broccoli at different stages, and few methods are listed in Supplementary Table S1 [28][29][30][31][32][33][34][35][36][37]. ...
Broccoli is one of the nutrient-rich vegetables that can easily be affected by bacteria and consumption of bacterial contaminated fresh products leads to a number of food borne illnesses. A multi-dimensional approach has been adapted to evaluate the freshness of broccoli considering four different mutually supporting techniques namely electronic nose, bacterial culture test, head sampler method with Gas Chromatography-Mass Spectrometry (GC–MS) and Fourier Transform Infrared (FTIR) spectroscopy. Electronic nose output variations from 0.05 V to 1.5 V and the presence of Staphylococcus, Salmonella and Shigella in the order of Zero, 10⁶ and 10⁵–10⁷ CFU mL⁻¹ were observed for fresh, half and completely contaminated broccoli samples. GC–MS data revealed the presence of acetic acid, hexanoic acid, nonanol evolved from half and completely contaminated broccoli samples. In addition, Principle Component Analysis, Centroid-link, and Completely-link cluster analyses were used on electronic nose data in correlation with other techniques for decision making.
... Studies established that a performed stretch-film is suitable for packing cauliflower, because heads in a package of non-performed one were covered by brown spots already at the third day [8,9]. For storing broccoli, it is recommended to choose a stretch film, because it allows to preserve organoleptic parameters of heads maximally, and A. Lucera with co-authors [10] accent attention on a fact that a performed stretch-film preserves organoleptic parameters and essentially prolongs the storage term of heads. The storage of Brussels sprouts in trays, wrapped in a stretch-film at temperature 0 о С, demonstrated better results in preserving the quality at long-term storage in experiments by S. Z. Viña [11]. ...
Tissues of fresh vegetables are characterized by the high quantity of moisture (80…96 %), active metabolism, low resistance to mechanical lesions, are spoiled fast. Metabolism in cells of tissues, so mass losses, depends on the content of water and dry substances. It is impossible to manage abiotic factors under conditions of open soil. So, there appears a necessity to study the influence of abiotic factors on the process of mass decrease at cauliflower storage that gives a possibility to prognosticate its mass losses and aptitude to storage. The aim of the study was to analyze the influence of weather conditions of the vegetation period of cauliflower, volume, specific mass and porosity of heads and packing methods on the intensity of natural mass losses of cauliflower at storage. The research gives a possibility to decrease natural losses of cauliflower heads and to prolong the storage duration of it. Cauliflower mass losses at the expanse of water evaporation depend on weather conditions of the vegetation period of the plant. It has been established, that there is a middle force reverse connection with the coefficient correlation r=–0,465 between the intensity of water evaporation at cauliflower heads storage and GTC, middle force connection with the coefficient correlation r=0,437 – with the average day temperature, and strong reverse connection r=–0,776 with the relative air humidity. There was elaborated the regression equation that gives an understanding about mass losses of cauliflower heads, packed in PF, at the expanse of water evaporation. The intensity of water evaporation of cauliflower at storage depends on package method. At packing in a stretch-film (SF), the intensity of moisture decrease, % a day, was the least, equal to 0,30–0,31. The ratio between moisture losses to ones of dry substances was 0,45–0,68. At packing in a performed stretch-film (PSF), the intensity of moisture decrease, % a day, was higher a little – 0,37–0,43. The more storage duration of cauliflower of late ripeness was provided by individual packing of heads in a polyethylene stretch-film. This packing type provided less total natural losses of products: in Skywoker F1– 6,0 %, in Kasper F1 and Santamaria F1 – 6,3 %. Natural losses for a day in variants with using a stretch-film were within 0,05–0,06 % depending on hybrid.
... Observing the results, it could be imply that MP escarole has sensibility to high CO 2 environments. The exceeded BI from PP and BOPP samples could be explain by the high CO 2 concentration inside these films, which also promoted undesirable odors in the product, symptom also reported in broccoli under high CO 2 conditions (>20%) in the package (Lucera et al., 2011). Although some authors recommend higher proportion of CO 2 then O 2 inside the packages to preserve the quality of most minimally processed leafy vegetables (Barth et al., 1993;Kaji, Ueno & Osajima, 1993), the balance of these gases must be manipulate in order to avoid CO 2 damage or anaerobic respiration. ...
... In general there were no important differences among treatments with a result slightly lower for AMA at day 21. Our results were similar or lower than the reported by Lucera et al., (2011) and Martínez-Hernández et al., (2013). Yeats and molds counts also decreased (1.5 Log UFC g -1 ) after sanitization, and the levels remain almost constant during storage (Fig. 4). ...
Fresh cut broccoli is a product with an increasing demand due to its convenience and proved benefits on human health, but is very perishable due to its high respiration rate. In order to maintain quality and extend shelf-life, two different approaches were carried out. Firstly, samples were packaged in sealed trays under passive modified atmosphere, and half of them were heated with air (48 C for 3 hours). All trays were stored at 5 C, and analyzed at 0, 7, 14 and 21 days. Basic physical-chemical parameters, chlorophyll a and b concentration, total phenolics, antioxidant activity, microbiological and sensorial quality were assessed. Results showed that heat treated broccoli showed poor sensorial quality due to off-odors and no increase in the shelf-life of the product was observed. For this reason, a second experiment was carried using passive and active modified atmospheres (10% O2 and 5% CO2) and compared to a control in air. Samples were also stored at 5 C and analyzed at 0, 5, 10 and 21 days. Modified atmosphere, either active or passive, allowed maintaining broccoli florets shelf-life up to 21 days, with higher quality compared to the control, being most suitable the passive modified atmosphere due to its simplicity and lower cost.
... Chapter 4 AdvAnces in modified Atmosphere pAckAging of fruits And vegetAbles 129 Costa et al. (2011) studied the effects of passive and active MAP conditions on the quality of packaged table grapes. They applied three oriented polypropylene (PP) films of different thicknesses (20, 40, and 80 mm, respectively) and various initial head space gas compositions (passive MAP and active MAP) to package the grapes. ...
This chapter is about the controlled atmosphere (CA) packaging technique. CA storage commonly uses low oxygen (O2) levels and high carbon dioxide (CO2) levels in the storage atmosphere combined with refrigeration. In CA storage, inside a food storage room is the gas composition that continually monitors and adapts to maintain the optimum concentration within completely close tolerances. Because CA storage is capital intensive and expensive to operate, it is more appropriate for those foods that are agreeable to long-term storage such as apples, kiwifruit, and pears. CA packaging is the enclosure of food in a gas impermeable package inside which the gaseous environment with respect to CO2, O2, N2, water vapor, and other trace gases has been changed and is selectively controlled to increase shelf life. Considering the definition, there are no CA packaging systems in commercial use. However, using the combination of O2 and ethylene (C2H4) absorbers, together with CO2 release agents in packaging, at least during the early stages of the storage life of the packaged product, could be classified as CA packaging. There are some functions for the generation and maintaining of CA including O2 removal, excess CO2 removal, and addition of air to replace O2 consumed by respiration, removal of C2H4, and in some cases addition of CO2. Selection of the appropriate functions and devices for generating and maintaining CA depends on what horticultural produce is stored and the storage conditions required for each produce. Research has shown that CA storage has positive, negative, and no effect on certain quality aspects of fruits and vegetables, such as physiological disorders, flavor and off-flavor, acidity, C2H4 production, respiration rate, volatile compounds, phytochemical compounds, color, etc. In this chapter all of these effects are discussed comprehensively.
... It is still not possible to make permeation tests at a temperature lower than 10°C by using the existing equipment; therefore, gas permeation tests were conducted at three different temperatures (10, 16 and 23°C) and the permeability values at 4°C were obtained by extrapolation using the Arrhenius equation (25). In particular, the oxygen transmission rate (OTR) was determined by means of an OX-TRAN ® (Model 2/20; Mocon, Minneapolis, MN, USA). ...
Ready-to-eat table grapes are a product with severe shelf life problems. Mass loss, colour changes, accelerated softening and mould proliferation can greatly influence quality decay of berries. Hence, the effects of different dipping treatments on the quality of packaged ready-to-eat table grapes have been successfully assessed. Various antimicrobial compounds (trans-2-hexenal, potassium sorbate, eugenol, cinnamon bark oil and ethanol) were used at different concentrations for dipping grape berries prior to packaging. All the samples were packaged in biaxially oriented polypropylene and stored at (4±1) °C. During the storage period, headspace gas composition, spoilage microorganisms, appearance of visible moulds and sensory quality were monitored. The composition of the headspace gas was typical of a non-climacteric fruit, thus demonstrating that the antimicrobial compounds did not affect product respiration rate. For the entire storage period, the bacterial counts did not grow significantly. On the contrary, mould proliferation on the product surface affected sensory properties until provoking product unacceptability. Relevant differences were found between the dipped and undipped samples. In particular, 50 % ethanol or 20 % ethanol combined with potassium sorbate (3 %) seemed to be very effective in preventing mould proliferation, thus promoting an increase in shelf life by about 100 %.
... In the unperforated BOPP packages a rapid drop in O 2 levels to 14-15% and an increase in CO 2 to 5-6% were observed after 6 days of storage, in comparison to the microperforated BOPP showing a slow decrease in O 2 levels to 18% and a slow build up of CO 2 to 2-3% after 6 days of storage. Similar changes in the O 2 and CO 2 levels were observed in broccoli florets using polypropylene based unperforated and microperforated packaging films (Lucera et al., 2011). ...
A study undertaken in Hervey Bay, Queensland, investigated the potential of creating an indigenous agribusiness opportunity based on the cultivation of indigenous Australian vegetables and herbs. Included were warrigal greens (WG) (Tetragonia tetragonioides), a green leafy vegetable and the herb sea celery (SC) (Apium prostratum); both traditional foods of the indigenous population and highly desirable to chefs wishing to add a unique, indigenous flavour to modern dishes. Packaging is important for shelf life extension and minimisation of postharvest losses in horticultural products. The ability of two packaging films to extend WG and SC shelf life was investigated. These were Antimisted Biaxial Oriented Polypropylene packaging film (BOPP) without perforations and Antifog BOPP Film with microperforations. Weight loss, packaging headspace composition, colour changes, sensory differences and microbial loads of packed WG and SC leaves were monitored to determine the impact of film oxygen transmission rate (OTR) and film water vapour transmission (WVT) on stored product quality. WG and SC were harvested, sanitised, packed and stored at 4°C for 16 days. Results indicated that the OTR and WVT rates of the package film significantly (P<0.05) influenced the package headspace and weight loss, but did not affect product colour, total bacteria, yeast and mould populations during storage. There was no significant difference (P>0.05) in aroma, appearance, texture and flavour for WG and SC during storage. It was therefore concluded that a shelf life of 16 days at 4°C, where acceptable sensory properties were retained, was achievable for WG and SC in both packaging films.,.
... Broccoli is a highly perishable vegetable that senesces rapidly; its storage life is reduced due to chlorophyll loss, floret yellowing, water loss, decay, and off-odors (Forney et al., 2003;Lucera et al., 2011). Changes in the color of fresh-cut broccoli, including L * , a * , and b * values as well as hue angle (h°), are shown in Figure 2. The L * values of fresh-cut broccoli changed slightly (within the range of 40.54-44.03) ...
The effects of immersion methods and concentrations of ozonated water on natural microbial contamination as well as the quality and sensory attributes of fresh-cut broccoli were studied. The first group of fresh-cut broccoli was immersed in air-ozonated water (containing 0.56 ppm ozone [O3]) for 5 min and remained immersed in this water for 5 min (i.e., low O3 concentration and long contact time; LL). The second group of fresh-cut broccoli was immersed in O2 gas-ozonated water (containing 1.60 ppm O3) for 5 min and remained immersed in this water for 3 min (i.e., high O3 concentration and short-contact time; HS). Fresh-cut broccoli treated with tap water served as the control. All samples were stored at 4°C for 6 days. The results revealed that washing fresh-cut broccoli with ozonated water (LL and HS) and tap water (control) reduced the amount of microbes compared with the initial microbial loads of unwashed fresh-cut broccoli. HS was the most effective treatment with regard to reducing aerobic bacteria, coliforms, and yeasts and molds throughout storage to ranges of 1.41-2.61, 0.55-1.75, and 1.46-1.71 log CFU.g-1FW, respectively. Furthermore, this treatment did not have negative effects on color (lightness, a*, b*, and hue angle values), chlorophyll content, or sensory attributes (overall visual quality, visible color, and odor). The LL treatment reduced the microbial counts in fresh-cut broccoli on the first day after the treatment; however, the quality and sensory attributes of the LL-treated broccoli were significantly decreased compared with the control. The results indicate that treating fresh-cut broccoli with water ozonated with a high concentration of O3 (1.60 ppm) for 5 min followed by immersion in the same water for 3 min reduces natural microbial contamination without any negative effects on the quality or sensory attributes of the broccoli.
... Microperforated films are commonly used for modified atmosphere packaging (MAP) 50 of fruits and vegetables with high respiration rates. Different headspace conditions 51 can be achieved in the package depending on the interactions between respiratory 52 activity of the packaged produce and gas transfer through the polymeric matrix and 53 microperforations (Lucera et al., 2011). This technique is often denoted equilibrium 54 modified atmosphere packaging (EMAP). ...
Heat transfer, as an operation that is present in the processing of almost every food, occurs repeatedly in baking, cooking, sterilizing, drying, and freezing in the food industry. Hence, realizing the heat transfer mechanism is essential to control food processing. Radiation as an efficient method of heat transfer at high temperature is the transfer of heat energy via electromagnetic waves that does not need any interaction between the heat source and heated body. In this chapter, the fundamental concepts of radiation heating are discussed. Electromagnetic waves and the electromagnetic spectrum, with special emphasis on thermal radiation, are explained. This is followed by discussion of the perfect black body, radiation of black body, and the role of black body radiation, in cooperation with the Stefan-Boltzmann law, Planck’s law, and Wien’s displacement law.
In this chapter, material balance and its importance in the field of food science/engineering have been discussed. To do this, first, material balance is explained in detail using mass, i.e., mass flows and not volumetric flows. It must be remembered that masses are additive, but volumes are not always additive. Then, we provide a brief explanation of what is a process and state that the chapter focuses on continuous material balance problems under steady-state conditions. The core of the chapter details a proposed strategy to solve simple and complex material balance problems. We developed a five-step procedure, which is explained and then applied in examples. The chapter concludes with 3 solved problems and then proposes 24 problems, each one with the corresponding answer.
This work evaluated the application of passive modified atmosphere packaging (MAP) technology for shelf life extension of ready-to-eat cherry tomatoes (cv. Tiny Bell), assessing the influence of perforated and non-perforated packaging films on product’s physicochemical, sensory and nutritional quality. Cherry tomatoes were washed, sanitized and packaged in continuous (PE) and perforated (pPE) polyethylene and perforated polypropylene (pPP). Packaged tomatoes and unpackaged tomatoes as control were stored at 7 °C for 21 d. MAP technology proved to be beneficial for cherry tomato postharvest preservation, showing reduced weight loss and sensory deterioration with respect to control. Moderate atmospheric modification achieved with the films studied (14–19 kPa for O2 and 2–3 kPa for CO2) showed a significant effect in climacteric peak magnitude. Color and firmness retention were observed for tomatoes in MAP conditions: hue angle was reduced by 5% in MAP in contrast to 18% in control, while firmness remained constant in MAP and showed a loss of 37% for control tomatoes. Lowest O2 concentrations achieved using PE packages (14.2 kPa) resulted in the highest firmness retention and greater reduction of respiration rate. MAP did not have an effect on nutritional quality, showing 11% loss of antioxidant capacity and 40% lycopene loss, as observed for control tomatoes. Considering sensory quality, ready-to-eat cherry tomatoes packaged in PE exhibited a shelf life of at least 21 d at 7 °C. This is the packaging condition recommended for cherry tomato (cv. Tiny Bell) postharvest refrigerated storage in the present study.
This study has been carried out to optimize an antimicrobial activity of flavonoid extract from pomelo peels against Staphyloccus aureus (S. aureus). A comparative analysis of total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity were done on two parts of peel which are albedo (inner peel) and flavedo (outer peel). Based on the result obtained, flavedo showed higher TPC, TFC and antioxidant activity (304.20 mg /g, 74.30 mg /g and 46.86 % respectively) when compared to albedo (150.98 mg /g, 52.97 mg /g and 24.70 % respectively). The effects of different extract concentration and pH on inhibition zone of S. aureus were optimized using Research Surface Methodology (RSM). The optimal condition of parameters was obtained based on the maximum zone of S. aureus inhibition at extract concentration of 200 mg/mL and pH of 4.8. The antimicrobial film has been developed by using optimal conditions by incorporating the flavonoid extract into chitosan polymer.
Ready-to-eat products are a rapidly growing sector in the market due to increased consumer demand for fresh, healthy, convenient, and additive-free products. However, freshly prepared food items are highly perishable and prone to major spoilage mechanisms of enzymatic discoloration, moisture loss, and microbial growth. Increase in market for ready-to-eat foods requires new preservation strategies to prolong the shelf-life of minimally processed (MP) food. The challenge is to develop and apply treatments effective on MP produce without compromising sensory quality through the shelf-life. This chapter reviews the different preservation and packaging methods applicable to MP produce to maintain quality and safety and increase the shelf-life. The use of intelligent indicators, active packaging technologies, and new-generation packaging materials in conjunction with MAP, irradiation, chemical treatments, coating, and hurdle technology is discussed in this chapter.
Fresh-cut fruits and vegetables have longer shelf lives when appropriate packaging materials having proper permeability properties are used. For this reason eight different packaging materials having different permeability properties were used and it was aimed to determine the appropriate packaging material and analytical and mathematical shelf lives of fresh cut red cabbage. Head space analysis, microbiological and sensorial analysis together with pH, weight loss (%) and colour analysis were performed. As a result of the study, it was determined that low density polyethylene (LDPE) film having 20 µm of thickness and 12276 cc/m 2-day of oxygen permeability was determined as the most suitable packaging material for packaging of fresh-cut red cabbage. Mathematical microbiological shelf life was determined as 12.33 days and both analytical microbiological and sensorial shelf lives were determined as 12 days. It was shown that Gompertz equation can be used in determination of microbiological shelf life of fresh-cut red cabbage since the analytical and mathematical shelf life results fit to each other. Also, the equation that can be used in calculation of shelf life of fresh-cut red cabbage when packaged with AYPE film having 12276 cc/m 2-day oxygen permeability was determined as log(Nt/N 0) = 6,83 × exp{-exp{[(0,80 * e)(6,83-t)/6,83]+1}}.
Fresh-cut fruits and vegetables have longer shelf lives when appropriate packaging materials having proper permeability properties are used. For this reason eight different packaging materials having different permeability properties were used and it was aimed to determine the appropriate packaging material and analytical and mathematical shelf lives of fresh cut red cabbage. Head space analysis, microbiological and sensorial analysis together with pH, weight loss (%) and colour analysis were performed. As a result of the study, it was determined that low density polyethylene (LDPE) film having 20 µm of thickness and 12276 cc/m2-day of oxygen permeability was determined as the most suitable packaging material for packaging of fresh-cut red cabbage. Mathematical microbiological shelf life was determined as 12.33 days and both analytical microbiological and sensorial shelf lives were determined as 12 days. It was shown that Gompertz equation can be used in determination of microbiological shelf life of fresh-cut red cabbage since the analytical and mathematical shelf life results fit to each other. Also, the equation that can be used in calculation of shelf life of fresh-cut red cabbage when packaged with AYPE film having 12276 cc/m2-day oxygen permeability was determined as log(Nt/N0) = 6,83 × exp{-exp{[(0,80*e)(6,83-t)/6,83]+1}}.
A simplified approach to predict the mass transport properties of micro-perforated films was presented in this work. In particular, the proposed mathematical model was based on a second-degree polynomial function. Different types of micro-perforated films with two thicknesses (35 and 25 µm) were tested for gas and water vapour permeability, under proper conditions. The films differed in both number of holes per unit area and hole diameter. Corresponding non-perforated films were also tested. The experimental data obtained were used to validate the model. Moreover, the surface response plot of the interactions between hole diameter and number of holes per area relative to oxygen, water vapour and carbon dioxide permeability were determined. Results of the mean relative deviation modulus (E%) between the experimental and predicted data confirmed the ability of the proposed model to predict the permeability of micro-perforated films. Copyright
This chapter concerns the modified atmosphere packaging (MAP) technique. MAP can be defined as the enclosure of food in a package in which the atmosphere is modified or altered to provide an optimum atmosphere for increasing shelf life and maintaining food quality. Modification of the atmosphere may be achieved either actively or passively. Gases used in MAP usually consist of O2, CO2, and N2, which are essential for the respiration of fresh fruits and vegetables. Among the gases used in MAP, just CO2 has significant nonselective antimicrobial influence on the product. Furthermore, optimal gas composition and the competitive effect on natural microflora on food pathogens play a significant role in product safety and inhibit foodborne pathogens. MAP, a technique used to extend the shelf life of fresh or minimally processed foods, refers to the development of a modified atmosphere around the product through the use of permeable polymeric films. The shelf life of the packaged products can be extended by 50–200% by using MAP, if the nutritional consequences of MAP on the packaged food products become an issue. Currently, MAP is integrated with several treatments such as heat treatment, irradiation, ozone, and preservatives for preservation of almost all foods in industrialized and developing countries to ensure secure microbial safety, stability, and sensory quality.
This chapter reviews the main detrimental phenomena involved in fruit and vegetable deterioration. To this end, three food categories are considered and some case studies presented. Moreover, the most recent approaches to preventing product deterioration are discussed.
Modified atmosphere packaging (MAP) for fruit and vegetables can be created either passively, by product respiration (passive MAP), or with intent, by substituting air with a proper gas mixture in the package (active MAP). This chapter examines the role and importance of passive and active MAP on fresh-cut produce shelf life. Design of MAP has progressed from a trial-and-error process to one that is mainly based on mathematical models developed with a good understanding of the underlying mechanisms. It is well recognized that the success of MAP greatly depends on the accuracy of predictive respiration rate models. Moreover, MAP design should take into strict consideration not only steady-state conditions but also the transient process to avoid the product being exposed for a long time to an unsuitable gas composition before reaching the adequate atmosphere. Hence, the chapter concludes with a review of case studies where steady-state or transient conditions were considered for optimizing package headspace.
To reduce quality loss of fresh‐cut green beans, different packaging systems were studied. In particular, samples were packaged in micro‐perforated and no‐perforated films and stored at 5 °C; unpackaged fresh‐cut green beans were also stored at the same temperature as the control. Headspace gas concentrations, mass loss, sensory quality and microbial proliferation were monitored for about 3 weeks. Results confirmed that selection of proper packaging is of crucial importance to create conditions able to guarantee the maintenance of product quality. Shelf life of fresh‐cut green beans packaged in the no‐perforated film (polyethylene, 25 μm) and in two micro‐perforated films (polypropylene films with 7 and 4 micro‐holes per package) was higher (19.2, 18.13 and 17.7 days, respectively) than that of the control or samples packaged in the micro‐perforated film with 12 micro‐holes per package (16.5 days).
In this work, the influence of packaging mass transport properties on quality loss of fresh‐cut cauliflower mixtures was addressed. The study was organised in two subsequent experimental steps; first, the selection of micro‐perforated packaging films was carried out by monitoring the package headspace gas concentrations of fresh‐cut white, green cauliflower and roman cabbage. Then, the effects of the barrier properties of the selected micro‐perforated film on shelf life of two different fresh‐cut cauliflower mixtures, stored at 4 ± 1 °C, were addressed. Results suggested that, among the investigated films, the micro‐perforated polymeric matrix with the lowest oxygen transmission rate value showed the best performance as it created the optimum headspace gas composition for each cauliflower variety, as well as, for the product mixtures. The appearance of visible moulds was the factor limiting product shelf life that accounted for about 18 days for both the investigated cauliflower mixtures.
The effects of dipping in antimicrobial solution and efficacy of proper film and modified atmosphere packaging conditions (MAP) on the quality decay of packaged fresh-cut butternut squash were investigated. The work was divided into three subsequent experimental trials: the first two were aimed to select the optimal packaging film mass transport properties, being micro-perforated and no-perforated films been tested. In the third experimental step, the best film (i.e., no-perforated oriented polypropylene, OPP40) was used to package sliced butternut squash under passive and active MAP. Each slice of product was dipped in aqueous solution of potassium sorbate, while no dipped samples were stored as the controls. During storage at refrigerated temperature (4 ± 1 °C) headspace gas concentrations, mass loss, microbiological and sensory quality were monitored. Results obtained from the preliminary pre-screening showed that micro-perforated films did not match fresh-cut butternut squash respiratory requirements. In these films a high proliferation of moulds occurred, probably due to elevated oxygen levels. Among the no-perforated films with different thickness, the OPP40 showed better performances. In the third trial samples dipped in potassium sorbate and packaged in OPP40 under active MAP recorded a shelf-life of about 22 days respect to the no-dipped samples packaged under both passive and active MAP that reached a shelf life of about 2 weeks.
The anti-yeast effects of several compounds at different concentrations were screened in vitro against main table grape spoilage yeasts. The compounds showing the most significant anti-yeast activity were applied by dipping to table grape, to evaluate the sensory perception. In a subsequent final step, dipping treatments with potassium sorbate, eugenol, citrus extract and ethanol, were applied to ready-to-eat seedless table grape, packaged in air or under modified atmosphere packaging (MAP). The in vitro test highlights good effects of cinnamon bark oil and citrus extract, even at the lowest concentrations used in this work. From a sensory point of view, the preliminary panel test selected potassium sorbate, citrus extract, eugenol and ethanol as most suitable substances. The in vivo application of active compounds showed that dipping in eugenol solution and ethanol (20 and 50 %) in combination with MAP increased shelf life of fruit if compared to the control sample (24.08, 28.47, 35.79 and 14.26 days, respectively).
Rates of ethylene production, respiration, and yellowing of broccoli ( Brassica oleracea L. Italica group) at 20°C were reduced by an aminoethoxy analog of rhizobitoxine (AAR) [L-2-arnino-4-(2-arnino-ethoxy)- trans -3-butenoic acid] and by sodium benzoate (SB). Loss of chlorophyll and ethylene production were retarded by concn of 5 × 10 ⁻³ M of AAR; at concn of 10 ⁻³ M or 5 × 10 ⁻⁴ M, the retardation was less pronounced. Yellowing and ethylene production were markedly reduced by SB at concentrations of 0.01M, 0.05M, or 0.1M. However, the latter two concentrations caused chemical injury and off-odor which resulted in unsalable quality. The data suggest that senescence of broccoli is related to ethylene production and that senescence can be retarded by inhibiting ethylene production.
Fresh asparagus, broccoli, and cauliflower were held under controlled atmosphere storage (CAS) and ambient air systems at 4°C for 21 days. Samples were examined on the initial day of experiments and after 2, 4, 7, 14, and 21 d of storage. On each day of analysis, color (value, chroma, and hue angle) was measured. Texture was measured as J needed to shear the vegetable/mm2 vegetable shear surface area. Total aerobic microbial populations were enumerated. Populations of total aerobic microorganisms were initially about 104 - 105 CFU/g on all three vegetables and grew to at least 107 CFU by d 21 of storage. CAS storage significantly reduced the growth of microorganisms on broccoli but had no significant effect with the other vegetables. Asparagus stored under CAS was easier to shear and had slightly higher hue angles than those of asparagus stored under air. Cauliflower stored under CAS showed less decline in value. CAS extended the length of time vegetables were subjectively considered acceptable for consumption. However, overall results indicate that quality of vegetables, as determined by objective measurements of color and texture, is not significantly influenced by CAS during refrigerated storage. Copyright © International Association of Milk, Food and Environmental Sanitarians.
The application of low oxygen through modified atmosphere packaging (MAP) is a technique used successfully to preserve the visual quality of lettuce and some other commodities. The expansion of use of low O2 via MAP to preserve quality of most commodities is limited by technical difficulties achieving target O2 concentrations, adverse physiological responses to low O2, and lack of beneficial responses to low O2. Low O2 often is not used simply because the physiological responses governed by the gas are not limiting quality maintenance. For instance, shelf life may be governed by decay susceptibility, which is largely unaffected by low O2 and may actually be exacerbated by the conditions encountered in hermetically sealed packages. Physiological processes influenced by low O2 and limit storability are discussed. The interdependence of O2 concentration, O2 uptake by the product, and temperature are discussed relative to requirements for packaging films.
Warm (20C) or cold (3C) broccoli florets (Brassica oleracea L., Italica Group) were sealed in bags of two types of nonperforated flexible polyvinylchloride film, TPM 87 or RMF 61, and kept at 5C for 7 days. Temperature of the warm florets cooled to 5C in ≈ 8 hours. Warm broccoli had 40% to 50% more CO 2 and 25% to 30% less O 2 than cold broccoli in packages of both film types 6 hours after sealing. After 48 hours, however, concentrations of CO 2 in bags of cold and warm broccoli had reached a steady state of ≈ 14.5% in TPM 87 bags and 6% in RMF 61 bags. Concentrations of O 2 were more variable. After 48 hours, O 2 concentrations were ≈ 2% to 4% in TPM 87 bags and 5% to 10% in RMF 61 bags. Initially, warm florets were rated lower for color, turgidity, and general appearance than initially cold ones after 7 days at 5C. Objectionable off-odors were formed from florets held in TPM 87 packages that had O 2 concentrations of <1.5%.
Controlled atmosphere (CA) conditions were assessed for long-term broccoli ( Brassica oleracea L. Italica Group) storage. Broccoli was stored for 6 weeks at 1C under N 2 containing the following percentages of CO 2 /O 2 : 0%/20%; 10%/20%; 6%/2.5%; I0%/2.5%; and 15%/2.5%. Color and chlorophyll retention was better under CA than in air. This improved retention was mainly due to increased CO 2 concentration. Storage under CA also delayed the development of soft rot and mold. However, after 6 weeks of storage under an atmosphere containing 10% or more CO 2 , the rate of respiration increased simultaneously with the development of undesirable odors and physiological injury. Among the atmospheres tested, 6% CO 2 and 2.5% O 2 was the best for long-term (>3 weeks) maintenance of broccoli quality while avoiding physiological injury.
The tolerances of horticultural commodities to CO2 are outlined, as are also the associated biochemical and physiological aspects of differences in tolerance between and within commodity types. These tolerances are related to responses to the use of modified atmosphere packaging (MAP) during storage. Commodities vary widely in their responses to elevated CO2, and low tolerance to the gas limits its use to maintain quality in some cases. Standard recommendations are generally those established to extend the storage period of any given commodity as long as possible, and safe atmospheres may differ substantially for shorter term exposures used in MAP. Use of MAP for storage of minimally processed products represents an important example of this, as storage periods and quality attributes required for commercial marketing of cut products can be very different from those of the whole product. Factors such as cultivar and postharvest treatment before imposing high CO2 can influence responses of commodities to CO2, but are rarely considered in cultivar selection or in commercial application. A better understanding of the physiology and biochemistry of commodity responses to CO2 is required for increased use of MAP.
The effects of cooling method and packaging with perforated film on broccoli (Brassica oleracea L. Italica group) quality during 2C storage were studied. Broccoli was either room-cooled, top-iced, or hydrocooled before being placing into storage for 14 days. Hydrocooling was the most rapid cooling method and resulted in the lowest vapor pressure deficits between the broccoli and the surrounding air. Hydrocooling and top-icing resulted in similar firmness and color retention. Broccoli that was hydrocooled and then overwrapped with perforated film lost less weight, was firmest, and retained color better than either top-iced or room-cooled broccoli.
Recent research has aimed to identify specific phytochemicals in Brassica vegetables, such as sulforaphane in broccoli, that may confer protection against cancer. Clinical, dietary, and policy implications are discussed.
Fresh broccoli (Brassica oleracea italica) heads with different weights were packaged in perforated (2 perforations each of 0.3 mm diameter) polypropylene (PP) film packages and stored at 5°C and 75% relative humidity (RH) in a cold room for 4 days under modified atmosphere packaging (MAP). It is concluded that 300 g broccoli samples compared to other packaging treatments could create low O2 and high CO2 concentrations, which resulted in a larger increase in the chlorophyll content. Further, the low temperature storage under the normal atmospheric gaseous compositions of O 2 and CO2 was not sufficient to avoid the senescence of the broccoli tissues in the unsealed control samples. The β-carotene content was largely unaffected under MAP, but the ascorbic acid content could be maintained in the broccoli florets in 300 g samples, while for stalks, it remained largely protected from the effect of MAP by the thick broccoli stalks. It could be concluded that perforated PP film packages (2 holes, each of 0.3 mm diameter) and having a film area of 0.1 m2 could be used to store broccoli for 4 days under MAP with maintenance of chlorophyll and ascorbic acid.
Modified atmosphere packaging (MAP) is a technology that is currently used for most packaged salads and fresh-cut vegetables, and to a lesser extent, fresh-cut fruit such as cantaloupe (Cucumis melo L.), pineapple [Ananas comosus L. (Merr.)], and apple (Malus x domestica Borkh.). In addition, about 750 million lb (340,200 Mg) of strawberries (Fragaria x ananassa Duch.), raspberries (Rubus idaeus L.) and sweet cherries (Prunus avium L.) are distributed in MAP annually. The fresh produce packaging industry has developed new trims to respond to increased produce consumption and changes in the use of trim packaging within different produce marketing segments. The produce film industry sold 60 million lb (27,200 Mg) of film in 1994, and in 2000 it is forecasted to sell 110 million lb (49,900 Mg), an increase of 83%. The distribution of film usage has also changed since 1994 when trim consumption patterns were as follows: 20% [12 million lb (5,400 Mg)] retail, 15% [9 million lb (4,100 Mg)] warehouse clubstores, and 65% [39 million lb (17,700 Mg)] food service. In 2000 it is projected that consumption patterns will be as follows: 25% [27.5 million lb (12,500 Mg)] retail, 20% [22 million lb (10,000 Mg)] warehouse clubstores, and 55% [60.5 million lb (27,400 Mg)] food service. These changes represent a 10% shift in trim market segment usage patterns away from food service applications to an increase of 5% for each of the retail and warehouse clubstore segments.
A procedure permitting the simple determination of the O2 and CO2 permeance of pouches used to pack respiring foods under real conditions is described. It is based on the measurement of the atmosphere changes in pouches filled with a gas mixture whose composition is calculated as a function of the permselectivity of film. The experimental curves (pCO2pCO2 and p(21-O2)p(21-O2)) versus storage duration are submitted to an exponential regression. The exponential coefficients are directly proportional to the O2 and CO2 permeances of the films. The method is designed for microperforated films (permselectivity close to 1), but can also be used to approximate the permeances of non-perforated films. The large variability of the permeances of the microperforated films is due to the heterogeneity of perforation density and diameter.
Broccoli was stored under modified atmosphere packaging (MAP) at 20 °C in perforated and unsealed polypropylene film packages for a storage period of 10 days to evaluate the effect of modified atmospheres on the chromatic changes. At the end of storage, MAP resulted in differential changes in the original green color of broccoli under different packaging treatments. Instead of conventional CIELAB color space system utilizing only L*, a* and b* values, the chromatic changes were analyzed as per L*C*h* color space system using lightness, chroma, and hue angle values to evaluate the final hue (color) along with its associated attributes. On 10th day of storage, broccoli samples kept under different modified atmospheres were observed to be yellow-green only for 4 holes, but between yellow-green and yellow for 8, 12, and 16 hole treatments, respectively. Further, the saturation of final hue attained under different packaging treatments kept on increasing in the order of 4, 8, 12, and 16 holes. On the other hand, broccoli kept in air in unsealed packages turned orange-yellow with higher saturation as compared with MAP samples. The direction of color difference for different treatments with respect to fresh broccoli samples was observed as light and the degree of color difference indicated that 4 and 8 hole treatments were only slight and medium light, respectively. The 4 hole treatment had best color retention as it had slightly saturated yellow-green hue, which was only slightly lighter than the fresh broccoli. Also, the results of sensory and visual analysis confirmed the results obtained from L*C*h* color space diagram and indicated that the modified atmosphere (6.1% O2 and 9% CO2) generated inside the perforated film packages having 4 macro-holes was the most suitable in maintaining the chromatic quality of the broccoli heads.
The ability of biodegradable films to prolong the shelf life of minimally process lettuce stored at 4°C was addressed. Four different films were tested: two polyester-based biodegradable films (NVT1, NVT2), a multilayer film made by laminating an aluminum foil with a polyethylene film (All-PE), and an oriented polypropylene film (OPP). Package headspace, microbial load and colour of the packed lettuce were monitored for a period of 9 days. A simple mathematical model was used to calculate the senescence level, whereas the re-parameterized Gompertz equation was used to calculate microbial shelf life of the fresh product. The fastest quality decay kinetic was observed for the lettuce packed in OPP, whereas the slowest one was detected for that in All-PE. Results suggest that the gas permeability of the investigated films plays a major role in determining the quality of the packed produce. Moreover, it was observed that biodegradable films guarantee a shelf life longer than that of OPP.
Central broccoli heads (cv. de Cicco) were harvested and treated with UV-C light (4, 7, 10, or 14kJm−2). All treatments delayed yellowing and chlorophyll degradation at 20°C but the irradiation dose of 10kJm−2 allowed retaining the highest chlorophyll content yet had lower amounts of pheophytins than every treatment other than 7kJm−2. This dose was selected to analyze the effect of UV-C on postharvest broccoli senescence at 20°C. The UV-C treatment delayed yellowing, chlorophyll a and b degradation, and also the increase in pheophytins during storage. The activity of chlorophyll peroxidase and chlorophyllase was lower in UV-C treated broccoli. Instead, Mg-dechelatase activity increased immediately after the treatment, but after 4 and 6d this activity was lower in UV-C treated florets than in controls. Treated broccoli also displayed lower respiration rate, total phenols and flavonoids, along with higher antioxidant capacity. The results suggest that UV-C treatments could be a useful non-chemical method to delay chlorophyll degradation, reduce tissue damage and disruption, and maintain antioxidant capacity in broccoli.
The ambient oxygen ingress rate (AOIR) method is an alternative/supplementary method to Ox-Tran for measuring the oxygen transmission rates of packages. The AOIR method facilitates high-capacity testing of packages under realistic food storage conditions, on the one hand, and on the other hand provides the possibility to predict the oxygen concentration over time in packages flushed with nitrogen at the time of packaging. The predicted oxygen concentration values showed good agreement with experimental values for flexible packages stored over a period of 91 days at 23°C and 38°C. The prediction of the oxygen concentration innitrogen-flushed packages may be a useful tool, e.g. in shelf life studies, in the selection of the optimal food package as regards to oxygen protection and within quality control purposes. Copyright © 2002 John Wiley & Sons, Ltd.
Earlier work showed that chlorophyll fluorescence changes of broccoli (Brassica oleracea L., Italica group) were associated with the accumulation of CO2 in modified atmosphere packages (MAP) during storage. This work was initiated to determine whether the chlorophyll fluorescence changes in broccoli from high CO2 MAP are persistent after the packages are opened and the broccoli is allowed to aerate. PD-961EZ bags, which allow the CO2 to accumulate (∼11 kPa CO2), were used in this study. During 28 days in MAP at 1°C, the broccoli gradually developed slight to moderate alcoholic off-odors and accumulated ethanol, acetaldehyde, and ethyl acetate in the tissues. These levels dissipated slightly on opening of the bags and holding the broccoli in 1°C air storage for 4 days. Chlorophyll fluorescence measurements (Fv/Fm, T12, Fmd, and ΦPSII) declined for broccoli with the accumulation of these anaerobic products and the fluorescence measurements recovered slightly after the bags were opened and the broccoli was held in air at 1°C for 4 days. Chlorophyll fluorescence measurements were found to be highly correlated with the anaerobic volatile content in broccoli during MAP storage and after opening of the MAP. Chlorophyll fluorescence measurements were also highly correlated with the perceived off-odors that were noted for the broccoli after longer storage durations in MAP.
Changes in the microflora of packaged (Resinite VF-71 film) and nonpackaged broccoli florets held at 8C for 7 days were analyzed. Oxygen and carbon dioxide concentrations, aerobic plate, coliform yeast/mold counts, and overall quality were determined. Level of O2 decreased from 15.58 to 5.15%, while CO2 increased from 2.88 to 8.22% after 94 h of storage. Within each microorganism group, similar growth trends were observed between the packaged and nonpackaged samples; however, the packaged samples consistently exhibited a statistically significant (p ≤ 0.05) lower microbial count compared with nonpackaged samples throughout the storage period. Packaged and nonpackaged florets retained their green color and no off-odor was detected; however, the nonpackaged florets were found to be less crispy than the packaged samples.
Changes in the microflora of fresh broccoli shrink-wrapped in film, sealed in gas-flushed film pouches, or stored on ice in cardboard crates and held at 1°C were analyzed. Growth trends for total aerobes, psychrotrophs, yeast/molds, members of Enterobacteriaceae, and lactic acid bacteria did not differ significantly between the packaging treatments (p ≤ 0.05). However, populations of total aerobes in unpackaged broccoli in its final week of storage (week 6) were significantly greater than that of packaged broccoli at week 6. Samples packaged in film remained higher in quality 2 to 3 weeks longer than control samples. Yellowing was the most obvious defect.
The ambient oxygen ingress rate method (AOIR) is an alternative method to Ox-Tran for measuring the oxygen transmission rates (OTR) of whole packages. The objective of the present work was (a) to compare OTR values obtained by the two methods, and (b) to evaluate the use of the AOIR method for measuring OTR at realistic food storage temperatures and humidity levels. The AOIR method gave equal OTR values compared to the Ox-Tran method for the five different types of whole packages used in the experiment, with OTR values in the range 0.06–1.48 ml O2/day. The repeatability of the AOIR method measured on an HDPE bottle was ±2.6% of the measured value in this experiment. This is slightly higher than the general specifications of the Ox-Tran method (1% of reading for packages). However, the AOIR method can be considered to be a reliable, precise and cheap alternative method to the Ox-Tran method for measuring OTR of whole packages. The capacity of the method is also high. The AOIR method showed satisfactory results when comparing OTR for packages tested under realistic food storage conditions covering 23°C/50% relative humidity (RH) and at 4°C/60% RH on the outside, combined with water (100% RH) or dry air inside the packages. Copyright © 2000 John Wiley & Sons, Ltd.
The exposure of intact broccoli to 6 mL/kg ethanol for 5 h was effective in inhibiting the senescence of fresh-cut broccoli florets. During the 8 d of storage at 10 °C, the weight loss, protein, and chlorophyll degradation of the treated broccoli florets were significantly retarded. The ethanol content of the ethanol-treated broccoli rose sharply and then descended rapidly to a level close to that of the control broccoli stored at 10 °C after 8 d. The acetaldehyde level of the treated broccoli was higher than that of the control broccoli over the whole storage period. The alcohol dehydrogenase activity of the treated broccoli was significantly higher than that of the control after 6 d. There had been higher activities of peroxidase, superoxide dismutase, and catalase in ethanol-treated broccoli. Our study showed that the fresh-cut broccoli treated with ethanol maintained better quality during the storage. Ethanol vapor would be commercially a good candidate for extending the shelf-life of fresh-cut broccoli florets and reducing the loss in postharvest.
The influence of film barrier properties on the quality loss of minimally processed grapes stored at 5 °C was addressed. Table grapes (Vitis vinifera cv. Italia) differing in quantity and frequency of irrigation, were tested with five different packaging films. Two commercially available films were used: a multilayer film obtained by laminating nylon and a polyolefin layer (NP), an oriented polypropylene film (OPP), along with three biodegradable polyester-based films (NVT-100, NVT-50 and NVT-35). The packed grape quality during storage was determined by monitoring the headspace oxygen and carbon dioxide concentration, the grape sensory qualities, and the viable cell concentration of the following spoilage microorganisms: total viable bacterial count, lactic acid bacteria, yeasts and molds. All the investigated films successfully preserved the quality of packed produce for the entire observation period (35 d). However, the best results were obtained using high barrier films such as NP and NVT-100. Slight differences were recorded between the two sets of table grapes in terms of respiratory activity and sensory quality.
Minimally processed broccoli was treated with UV-C light (8 kJ m−2) and subsequently stored for 21 days at 4 °C. The UV-C treatment delayed yellowing and chlorophyll degradation during storage. Treated broccoli florets displayed lower electrolyte leakage and respiratory activity, indicating higher tissue integrity. Treated samples showed higher phenolic and ascorbic acid contents as well as higher antioxidant activity than controls. Treated samples also had a higher content of soluble sugars, but no differences in the content of soluble proteins between control and treated samples were detected. The UV-C treatment also affected bacterial and mould populations. After 21 days at 4 °C the number of colony-forming units of both populations was lower in treated than in control broccoli florets. The results suggest that UV-C treatment reduces tissue damage of minimally processed broccoli during storage at 4 °C, thus maintaining nutritional quality and reducing microbial growth. Copyright © 2007 Society of Chemical Industry
The effect of cutting shape (cubes or slices) and storage temperature (5 °C, 10 °C, and 20 °C) on overall quality of fresh-cut papaya were investigated. CO2 production, color, firmness, total soluble solids (TSS), weight loss, overall quality, ascorbic acid, β-carotene, and antioxidant capacity were evaluated as a function of shelf life. CO2 production was high on day 0 for cubes and slices with an average of 150 and 100 mL/ kg/h, respectively. Storage temperature did not affect color changes; however, lower temperatures prevented loss of firmness. Fresh-cut papaya stored at 20 °C showed the lowest TSS value and the highest weight losses. Shelf life based on visual quality ended before significant losses of total ascorbic acid, b-carotene, and antioxidant capacity occurred. In general, quality parameters were not affected by shape. However, slices stored at 10 °C and 5 °C had a shelf life of 1 d and 2 d longer than cubes, respectively.
Treatments with hot air were applied to broccoli (Brassica oleracea L) florets to investigate the effect on several quality and senescence parameters. To select the optimum treatment, florets were treated with different combinations of time/temperature ranging from 1 to 3 h and 37 to 50 °C and then placed in darkness at 20 °C. Most treatments delayed yellowing and loss of chlorophylls, except those performed at 37 °C, which accelerated senescence. Treatment at 48 °C for 3 h caused the highest delay in chlorophyll loss and was chosen to analyse its effect on quality and senescence. Non-treated florets showed yellowing and reduced their chlorophyll content during storage. Heat treatment delayed the onset of chlorophyll catabolism by 1 day and slowed down the rate of degradation. Treated florets also showed lower losses of total sugars and proteins and an inhibition of protein solubilisation. Control heads showed an increment in CO2 production, which was not detected in heat-treated florets. Total antioxidants decreased and thiobarbituric acid-reactive substances (TBARS) increased during storage. The treatment delayed the decrease in antioxidant content and inhibited the increment in TBARS. In conclusion, treatment at 48 °C for 3 h delayed broccoli senescence at 20 °C and contributed to maintaining an overall better quality of the product. Copyright © 2005 Society of Chemical Industry
Modified atmosphere packaging (MAP) is increasingly used with minimally processed produce. Increased MAP usage coupled with negative environmental views associated with nondegradable synthetic packaging materials creates a need for biodegradable films. Zein films plasticized with oleic acid had been proposed for biodegradable packaging applications. Conversion treatments including lamination and coating films with tung oil were reported to improve water vapor and gas barrier properties of films. In this work, the ability of treated and untreated zein films to perform as MAP for fresh broccoli florets was investigated. Florets were packaged in glass jars sealed with zein films and stored under refrigeration for 6 d. Headspace oxygen and carbon dioxide concentrations were monitored during storage. Tested films allowed the development of modified atmospheres inside the packages. Broccoli florets packaged in the test films maintained their original firmness and color.
The possibility of using cactus pear fruit (Opuntia ficus indica Mill, cv. Gialla) to produce ready-to-eat fruit was investigated. Changes in sensory quality and proliferation of spoilage microorganisms on lightly processed and packaged fruit as a function of storage temperature and modified atmosphere packaging were measured. The shelf life of the samples was kinetically modelled in order to check the effects of storage temperature and to assess the most relevant microbial indices for the product quality. Minimally processed cactus pear fruit had longer shelf life at 4 °C than at temperatures recommended for whole fruit when these were greater than 4 °C. The packaging of processed cactus pear fruit in modified atmospheres during storage resulted in a homogeneous bacterial population compared to that isolated from fruit stored in air, and favored the growth of Leuconostoc mesenteroides. Our results suggest that mathematical modelling might allow the industry to use more objective measurements to determine the shelf life of their products.
In this work different packaging strategies aimed to prolong the shelf life of minimally processed lampascioni are presented. In particular, two different treatments prior to packaging were tested: dipping in a solution containing citric acid (1%) and calcium chloride (8%), and coating with sodium alginate (5%), in combination with citric acid (1%) and calcium chloride solution (8%). The treated samples were packaged using two types of polymeric films: a commercially available oriented polypropylene film (OPP), and a polyester-based biodegradable film (NVT2). The investigated produce was stored at 5 °C for approximately 20 days. Microbial populations, pH, weight loss and visual quality were monitored for the entire observation period. In order to determine the respiration activity, O2 and CO2 concentration were monitored not only in OPP and NVT2 packages but also in the headspace of an aluminum-based package. Results show that, among the packaging strategies investigated in this work, the coated lampascioni packaged in NVT2 film were best preserved over the entire storage period. In fact, the alginate coating, combined with the gas barrier properties of the NVT2 film, can delay the lampascioni respiratory activity and the browning process, as well as the microbial growth, allows prolonging the shelf life of the investigated fresh-cut produce.
A simple and cost-effective ethanol vapor treatment using alcohol powder, which gradually diffuses ethanol vapor, was conducted to inhibit the senescence of harvested broccoli (Brassica oleracea L. var. Italica) and to clarify the mechanism for the maintenance of the green color in the florets. Six branchlets were placed in a polyethylene bag with 0, 3, 6, or 12 g of alcohol powder and stored at 20 °C in darkness. The untreated broccoli florets started to turn yellow at 3 days in storage (DIS). The broccoli florets treated with 3 and 6 g of alcohol powder finally turned slightly yellow at 5 DIS. The yellowing was inhibited with 12 g of alcohol powder over a 5-day storage period. Ethylene production of untreated broccoli was highest at 2 and 3 DIS; after that, it decreased. However, in broccoli treated with alcohol powder, ethylene did not increase. 1-Aminocyclopropane-1-carboxylic acid (ACC) contents in untreated broccoli florets increased gradually, whereas in those treated with alcohol powder contents increased dramatically at 4 DIS. ACC oxidase activity in untreated broccoli florets also increased at 2 and 3 DIS, at the same time as the increase in ethylene production. There was no increase in those treated with alcohol powder. These results revealed that treatment with alcohol powder was effective for prolonging the shelf life of broccoli because it suppressed ethylene production by inhibiting ACC oxidase activity.
Broccoli (Brassica oleracea L. var. Italica) heads were packaged using 3 types of polypropylene films: macro-perforated (Ma-P), micro-perforated (Mi-P) and non-perforated (No-P), and then stored at 1 °C for 28 days to study the effects of modified atmosphere packaging (MAP) on the maintenance of quality and functional properties by comparison with non-wrapped heads. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by weight loss, yellowing, chlorophyll degradation and stem hardening. Also, a rapid decrease in total antioxidant activity (TAA), ascorbic acid and total phenolic compound concentration was observed. Conversely, in those heads packaged under MAP, especially for Mi-P and No-P, all changes related with loss of quality were significantly reduced and delayed with time. Additionally, TAA, ascorbic acid and total phenolic compounds remained almost unchanged during the whole period. Thus, broccoli packaged with Mi-P and No-P films had prolonged storability up to 28 days with high quality attributes and health-promoting compounds, this period being only 5 days in unwrapped control broccoli.
Florets of broccoli (Brassica oleracea var. italica L.) and the youngest fully expanded leaf detached from pak choy (Brassica rapa var. chinensis) were treated with 1-methylcyclopropene (1-MCP) overnight (16 h) and then stored at supermarket retail temperature (10 °C). A concentration of 12 μl l−1 was considered optimal for both pak choy leaves and broccoli florets. 1-MCP increased shelf life of broccoli florets by just greater than 20% but had little effect on pak choy shelf life (increases between 10 and 20%) in the absence of exogenously applied ethylene. Multiple applications had no further impact while 1-MCP needed to be applied as soon as possible after harvest to have maximal effect. If 1-MCP treatment was applied overnight at 20 °C prior to storage at 10 °C, its effect was slightly increased. However, 1-MCP did protect broccoli and pak choy from the effects of exogenously applied ethylene (0.1 or 1 μl l−1) suggesting it may be useful during retail or storage with ethylene-producing commodities. Differences between the efficacies of 1-MCP on florets compared with leaves are discussed.
The aim of this work is to evaluate the shelf life of Stracciatella cheese packaged in a protective atmosphere, using 4 different CO(2):N(2):O(2) gas mixtures [50:50:0 (M1), 95:5:0 (M2), 75:25:0 (M3), and 30:65:5 (M4) vol/vol] and stored at 8 degrees C. Cheese in traditional tubs and under vacuum were used as the controls. Results showed that the modified-atmosphere packaging, in particular M1 and M2, delayed microbial growth of spoilage bacteria, without affecting the dairy microflora, and prolonged the sensorial acceptability limit.
Minimally processed fresh (MPF) fruits and vegetables are good media for growth of microorganisms. They have been involved in outbreaks because of the consumption of products contaminated by pathogens. They are also sensitive to various spoilage microorganisms such as pectinolytic bacteria, saprophytic Gram-negative bacteria, lactic acid bacteria, and yeasts. Contamination of MPF fruits and vegetables occurs at every stage of the food chain, from cultivation to processing. Polluted environments during cultivation or poor hygienic conditions in processing increase the risk of contamination with foodborne pathogens. Although MPF fruits and vegetables may harbor psychrotrophic microorganisms such as fluorescent pseudomonads or Listeria monocytogenes, good control of refrigeration temperature limits growth of spoilage and pathogenic microorganisms. Modified atmospheres are often efficient to maintain or improve visual organoleptic quality of MPF fruits and vegetables, but their effects on microorganisms are inconsistent. Chemical disinfection can partially reduce the initial bacterial contamination; irradiation seems to be more efficient. The applications of legislations and quality assurance systems to control contamination, survival, and growth of foodborne pathogens in MPF fruits and vegetables are discussed.
Overall quality of the FC-UP, W-PVC and fresh-cut florets broccoli packaged in the OPP20, MP-PP-20, MP-PP-7 films. The curves are the best fit of Eq
- Fig
Fig. 6. Overall quality of the FC-UP, W-PVC and fresh-cut florets broccoli packaged in the OPP20, MP-PP-20, MP-PP-7 films. The curves are the best fit of Eq. (2) to the sensorial data. The data represent the mean of seven replicates ± standard deviation.
Disorder in cabbage, bunched broccoli and cauliflower shipment to the New York market
- M J Ceponis
- R A Cappellini
- G W Lightner
Ceponis, M.J., Cappellini, R.A., Lightner, G.W., 1987. Disorder in cabbage, bunched broccoli and cauliflower shipment to the New York market, 1972–1985. Plant Disease 71, 1151–1154.
Fruits, vegetables and grains Food Microbiology, Fundamentals and Frontiers
- R E Brackett
Brackett, R.E., 1997. Fruits, vegetables and grains. In: Doyle, M.P., Beuchat, L.R., Montville, T.J. (Eds.), Food Microbiology, Fundamentals and Frontiers. American Society for Micro-biology Press, Washington, DC, pp. 117–126. 347–360.
Fruits, vegetables and grains
- Brackett
Disorder in cabbage, bunched broccoli and cauliflower shipment to the New York market, 1972–1985
- Ceponis