Know Your Healthy Berries

Application frozen berries and jams 1641 Potential techniques for berries

Berries can be frozen in syrup or as individual berries. As individual berries, they may be frozen on a tray or individual quick frozen (IQF) on a belt in an air-blast or cryogenic freezer. Depending on the final product, different freezing procedures might be appropriate (Reid, 1996). Freezing berries by fluidization yields products of the same quality as does liquid nitrogen freezing, but requires less time (Miller and Butcher, 2000). Strawberries for commercial preserves, jam, and jelly manufacture are usually washed and capped, frozen with either 5 1 or 4 1 fruit sugar ratio, and then thawed before processing (Sistrunk et al., 1982). The appearance of the frozen berries is influenced by the method of mixing the sweetener with berries rather than the sweetener itself (Aref et al., 1956). One possible way to pre-treat berries is to use calcium, which fortifies the fruit by changing the pectin structure (Poovaiah, 1986 Garcia et al, 1996). The use of PME enzyme has proved to be an...

Conventional Plant Breeding

Peas were normally round-seeded, starchy and bland, harvested at maturity for storage and later consumption as soup or pease pudding. Knight developed sweeter peas with wrinkled seeds from 1787 onwards. His new peas came to be highly regarded, and over the next half-century he revolutionised green peas as a vegetable. Through his good friend Sir Joseph Banks, one of Knight's new varieties was transmitted to Australia with Philip Gidley King when he returned as Governor of New South Wales in 1800. This is the Tall Marrowfat that King records in his correspondence with Lord Hobart in 1803.29 Knight also bred many new kinds of fruit tree, and several notable strawberries, such as the Downton (1817) and the Elton (1828). The latter also made its way to New South Wales.30

Introduction the effects of freezing and thawing on berry texture

Freezing and subsequent frozen storage causes excessive softening of berries, and frozen strawberries are characteristically very soft and moist. The great susceptibility of strawberries to textural damage is due to their low solids content, large cells and thin cell walls. During freezing the ice crystals formed rupture the parenchyma cell walls and induce loss of turgor. These structural characteristics account for the loss of instrumental firmness. The right choice of cultivar is important in producing a high-quality frozen product (Oswin, 1979) and so grading involving possible defects, size and texture is necessary before freezing. The rate of freezing is a critical issue with regard to tissue damage. The fast freezing method allows better retention of texture, and higher texture values can be obtained with freezing in liquid nitrogen and plate freezing. However, berries immersed in liquid nitrogen may crack due to ultra-rapid freezing. Slow freezing results in formation of large...

Sensory perception of texture

The sensory quality of fresh strawberries is influenced by cultivar, maturity, site, season and agronomic practice. The texture profiling technique has been used to assess sensory perception of the texture of strawberries (Szczesniak and Smith, 1969). Fresh berries are firm, plump, low in cohesiveness and moderately juicy. Sensory firmness, cohesiveness and degree of fibrousness decrease with increased ripeness. Not all berries have good freezing characteristics and berries with good quality should be chosen for freezing. Strawberries retain much of their natural flavor and color under freezing, frozen storage and thawing but suffer serious softening in texture and release more juice than the fresh product. This loss in sensory firmness can be characterized by a moist, soft and limp appearance, poor shape retention and a tough texture of the interior fibers.

Changes in water binding properties

The juice loss from strawberries has been measured by quantifying the amount of moisture released to filter paper during mechnical mastication by the Texturometer (Szczesniak and Smith, 1969). Frozen berry releases juice in great quantity. It has been demonstrated in one study that the texture of fresh samples is correlated with the drip loss during thawing (Lacroix et al., 1985). Freezing method and field (F) greenhouse (G) cultivation had very significant influence on water drip (Agnelli and Mascheroni, 2002). Up to 60 reduction in drip loss was obtained by freezing the field cultivated strawberries in liquid nitrogen following storage in an air-blast freezer.

Methodology for measuring actual and estimating bruise volume and bruise threshold

The machine vision procedure using visible and NIR ranges to detect bruising in sweet cherries was studied by the Daniel Guyer research group at Michigan State University, USA (Guyer et al, 1996) and in strawberries by the Masateru Nagata research group at Miyazaki University, Japan (Shrestha, 2002). This image processing technique can be used to detect, measure actual and estimate bruise volume and bruise threshold. For cherries, the bandpass filters that enhance the intensity contrast between bruised and unbruised fruits were determined. An optimum combination of two wavelengths is identified at 750 nm (NIR range) and 500 nm (green range). An optimum single wavelength is identified at 750 nm. Bruise detection via infrared edge detection had the least error potential which suggested the idea of implementing edge detection to detect the transitive area between good and bruised tissues. For strawberries it was concluded that the a* level of the L*a*b* model was especially able to...

Processed fruit firming by infusion of gelling agents

Hormones Pregnancy

In the case of strawberry slices, as proposed by Barton, the use of pectin and alginate before freezing made it possible to maintain the shape, weight and colour of the fruit to a greater degree than was the case for untreated fruit this was particularly so when high methylated (HM) pectin was used. Preliminary vacuum impregnation of strawberries in solutions containing gelling agents was proposed by Cierco (1994) as a new method for improving the quality of frozen fruits. Using this process, frozen thawed strawberries were obtained which maintained the features and the taste of fresh ones even after several years' storage at -20 C and that are usable for traditional pastry-making.

Mechanical properties

Measuring the mechanical properties of strawberries by normal compression is difficult, since the shape and size of strawberries vary a lot. It is also impossible to take a cylindrical sample from strawberry, as the structure is very unhomogenous. Puncture testing has most often been used in strawberry texture measurement (Bourne, 1979). By utilizing a puncture-penetration method it has been possible to measure both the skin toughness and flesh firmness of different strawberry varieties before freezing and after freezing and thawing and to grade species according to their suitability for freezing (Lacroix et al., 1985). The skin toughness of fresh samples for 25 different strawberry varieties varied from 3.19-6.19 N, and after freezing (-50 C 20-25 min), frozen storage (three months at -30 C) and thawing (at 3 C for 48 h) from 1.32-2.92 N. In the same way, flesh firmness of fresh berries was in the range 5.34-15.28 N. After freezing and thawing it was 1.75-6.28 N indicating...

Spirulina As A Natural Therapeutic Intervention For Inflammation And Oxidative Stress In Aging

Classified as a cynobacteria (blue-green algae) Spirulina is abundant in phycocy-anin, which gives it a blue pigmentation. The large amount of chlorophyll accounts for the vivid green color. Other additional carotenoids present contribute to the rich pigmentation of Spirulina. Interestingly, in nature, fruits and vegetables that have brighter and deeper hues often supply more antioxidants per serving then their paler cohorts.78 A familiar example is found in the blueberry. The deep pigmentation of the blueberries produces a high ORAC value. The ORAC of blueberries is 2600 mol Trolox equivalents gram, whereas the ORAC for Spirulina is 13,000.29 Spirulina has demonstrated that it has antioxidant activity, which scavenges peroxyl radicals.79 It also contains components that act as inhibitors of cylooxygenase (COX), one of the main biological activities of nonsteroidal anti-inflammatory drugs.80

Potential techniques for jams

The pre-freezing treatments of berries are particularly interesting for the jam-making industry because fresh berries are not available for jam-making in all seasons. Furthermore, harvesting conditions and the size and chemical structure of berries selected for jam-making vary. For industrial jam-making Thawed berries Fig. 16.3 Firmness of pretreated thawed strawberries. Error bars are shown as means SD (n 6). a-e Means with the same letter are not significantly different as determined by Tukey's test (p 0.05), 1a. Reference, 1b. Water in a vacuum, 2a. it is of primary importance to ensure both consistent jam-making conditions and the integrity of berries (Suutarinen, 2002). Firmness ofjam strawberries pre-treated with CaCl2 and PME in a vacuum was higher than that of untreated berries or berries pre-treated with different methods (Suutarinen, 2002 b) (Fig. 16.4). Dipping of strawberries into a CaCl2 solution with PME in a vacuum resulted in a significantly different sensory profile...

Preserving fruit firmness by calcium or polyamines infusion

The process of dipping whole fruits in aqueous preservative solutions, which is improved by vacuum application, has been used to prolong the post-harvest shelf life of many products apples (Scott and Wills, 1977, 1979 Lidster et al., 1986), lemons (Valero et al., 1998a, b), avocados (Wills and Sirivatanapa, 1988), mangoes (Tirmazi and Wills, 1981), tomatoes (Wills and Tirmazi, 1979), strawberries (Ponappa et al., 1993). The compounds Calcium lactate infusion in fresh whole or sliced strawberries improved their texture and reduced their weight loss measured after canning (Main et al., 1986) owing to the presence of calcium which reinforces the cell wall structure by forming pectates. In addition, Main et al. (1986) showed that calcium impregnation on whole or sliced strawberries prior to freezing only slightly improved the resistance of thawed fruit to shear. The low effectiveness of calcium in improving firmness was explained by insufficient demethylation of endogenous pectins in the...

Years old 18 months after my relapse

I sit with my friends waiting for my kids' races. Last week my scans were clear - no cancer anywhere. Today I am celebrating with my friends so our ice-box contains strawberries and a bottle of wine. I overhear a bored dad saying, 'I hate sports day, don't you ' Immediately I think back to last year when my cancer was at its worst and I sat through sports day crying for the children I might not see grow up. But now things are different and I am 'all-clear'. Today, the sun seems hotter, the grass greener and the cries of happy children never more joyful. Today, sports day seems the most wonderful occasion ever and I laugh out loud when I see Adam jumping his way to third place. Winning Olympic gold could not beat this Today I make a promise to myself I shall never miss another sports day or any of my children's precious days. I shall aim for every sports day and remember my survival on this day. This year - this sports day - I am seeing my children...

Superficial and Cavernous Hemangiomas

The familiar bright-red, raised strawberry tumor has been seen by all physicians. Strawberries have to grow, and they start from a small beginning. The parents are usually the first to notice the small, red, pinhead-sized, flat lesions. They are noticed at, or soon after, birth. These red tumors can occur on any area of the body and can begin as small lesions and stay that way, remaining as superficial hemangiomas, or they can enlarge and extend into the subcutaneous tissue, forming a cavernous type. The enlargement can occur rapidly or slowly. Occasionally there can be multiple lesions.


Firmer fruit bounced out at higher frequencies. The same device was used to sort blueberries based on firmness and shelf life (Hamann et al., 1973). They reported that bruised berries bounced from the vibrating trough at lower frequencies. Bower and Rohrbach (1976) also developed and tested a similar vibration device to sort blueberries. They reported that vibration sorting was effective in separating most good fruit from damaged fruit, but it was not effective in separating blueberries based on firmness and shelf life. Wolfe et al. (1980) reported that vibration sorting of fruit into different quality grades was not accurate enough to meet the marketing requirements. This is not surprising since the vibration behavior is also affected by the mass, size and shape of the fruit. Vibration tests are suitable when products are relatively uniform in size and shape, and when there exists a large variation in the textural attributes. A commercial pilot tomato sorting system was developed,...


The fluid contained within an amebic liver abscess is usually dark reddish-brown and has been described most often as anchovy sauce or anchovy paste. This material, which is typically sterile and consists of a mixture of blood and destroyed liver cells, has also been described as resembling chocolate sauce, crushed strawberries, or wine dregs. Amebic trophozoites are rarely found within the pus of a liquefied amebic abscess, but they are found characteristically in the zone of necrotic tissue adjacent to the outer abscess wall. Demonstration of trophozoites is more frequent during the earlier stages of an abscess and is less likely in an older abscess with a thick fibrotic capsule. Histologic examination during the early stages reveals cytolysed and degenerated liver cells, erythrocytes, a few leukocytes, and occasionally an ameba. As the lesion progresses, a well-defined wall of connective tissue appears and surrounds the cavity that contains necrotic liver tissue. In an amebic...


Figure 16.1 shows the cross-section of a strawberry. Strawberry is composed of different tissues which differ in terms of chemical structure and microstructure. Vascular tissue composed of long fibers and pith forms the skeleton of the strawberry structure. Epidermal cells form the outer layer. Vascular bundles beginning from the achenes and connecting to the pith play a very important role in the texture of strawberries. The second layer is composed of hypodermal cells and the third layer of cortical cells (cortex). In cortical cells the pectins in the middle lamella have an important role in cementing the cells together. In plant tissue, the maintainance of shape is based on turgor pressure within individual cells. Freezing and thawing has a highly detrimental effect on cortical parenchyma cells which have large cells and thin cell walls. The degree of cortical cell wall rupture during freezing determines the extent of textural change. Frozen berries also showed plasmolyzed cells.

Blossom Collection

A simpler solution seems to be that of continuing to cut the blossoms by hand, but facilitating their placement into containers by using the described sucking system. However, the scissors would have to be removed and the machine placed in a position which allows closed flowers to be sucked up as well. This would seem possible through the use of facilitating machines of the type used for picking asparagus or strawberries the picker's stance would be improved and the harvesting bags brought nearer to ground level, thereby allowing the blossoms to be sucked up. A machine of this kind is under study at the moment at our department in Florence.

High pressure

Strawberry slices were treated in a liquid medium containing the PME enzyme (200 L 100 g fresh strawberries PME activity 100 000 nkat ml) and calcium ions (1 CaCl2 solution) under vacuum (13.3 kPa for 10 min) prior to high-pressure processing. It was possible to improve the firmness of the foodstuff while simultaneously deaerating the product. It has been reported that high-pressure treatment (50 MPa min up to 500 MPa temperature 25 C and holding time 15 min) may even increase the activity of PME (Stute et al., 1996). A slight increase in firmness of berries was found when berries were soaked in a liquid containing either enzyme or calcium ions. The best result was obtained when both enzyme and calcium ions were present in the soaking liquid, giving a firmness that was about nine times higher than that for the berries that were not pre-treated at all (Stolt et al., 2001).

Bacterial infections

These two treponematoses are related to syphilis, although epidemiologically behave in an endemic fashion. Yaws, also called pian or frambesia, is a disease caused by T. pertenue with identical morphology to T. pallidum. It is endemic to all tropical areas around the world from Central and South American to Africa, Asia, Australia, and the Pacific islands. It is also acquired during childhood. The clinical manifestations go through the three classical stages of early, secondary, and late lesions. The primary lesion is chancroid in appearance, whereas the secondary lesions are papillomatous verrucous and similar to condylomas. In skin they resemble raspberries, giving origin to its French name, frambesia. Bone involvement can be rather destructive, ending in severe deformities and mutilations. Tertiary lesions can be gumma-like and achromic, as in pinta, and can produce palmoplantar hyperkeratosis. Treatment is again based on the use of penicillin.


Softening caused by freezing-thawing can sometimes be minimized by dipping the tissue in different solutions before freezing. Much of the softening results from degradation of the middle lamella of the walls of cortical cells with increased release of pectins from the cell walls. In many fruit, such as tomato, endo-polygalacturonase begins water solubilization of pectins while exo-polygalacturonase completes hydrolysis (Perkins-Veazie, 1995). Firmness changes in strawberries during senescence and in the absence of polygalacturonase have been linked to changes in ionic stability of the middle lamella. In addition, to enhance the activity of pectinesterase naturally present in fruit, commercially available PME preparations can be used. PME catalyzes cleavage of the ester bonds between the methyl and the carboxyl groups of pectic substances, thus forming anionic COO- groups with which calcium ions can form salt bridge crosslinks. Calcium pectate is thus formed, which is assumed to anchor...

Quasistatic loading

Considerable research has been reported on firmness measurement of small fruits such as cherries and berries based on the deformation measurement corresponding to a specific load (Bernstein and Lustig, 1981 Diener et al., 1969 Lusting and Bernstein, 1987 Parker et al, 1966 Rohrbach, 1981 Rohrbach and Mainland, 1993 Timm et al., 1996 Wolfe et al., 1980). An instrument developed by BioWorks, Inc. (Stillwater, Oklahoma, USA) based on the original design of Timm et al. (1996) was recently available for measuring the firmness of small fruits. Fruit are placed on 25 shallow pockets

Partial air drying

Thawing in fresh and pre-dried strawberries were studied in order to quantify the possible cryoprotective effect of osmotic treatment with sucrose solutions. Good mechanical properties were retained to a higher degree by air drying than osmotic drying however, after freezing-thawing these differences were not significant (Chiralt et al., 2001).

Misguided Goals

What else is nonsense Putting genes for Antarctic fish 'antifreeze' serum glycoproteins into fruits like tomatoes or strawberries to help them retain texture in cold storage comes into the 'downright stupid' category of potential modifications. These interesting glycoproteins contain repeating units of alanine-alanine-thre-onine, with each threonine linked to a disaccharide consisting of galactosyl-N-acetyl galactosamine.5 The genes for several new enzymes would be necessary for this synthesis in plants, not just one, so the production of this glycoprotein in plants would be technically difficult to bring about.

Dynamic loading

Most quasi-static methods measure either force or deformation or both from a small local area of food samples. Many foods, especially meats and raw fruits and vegetables, exhibit considerable variability in the mechanical properties within the same food sample. The dynamic force deformation methods discussed herein are less influenced by the local properties and are more representative of the overall mechanical properties of a food sample. Dynamic force deformation methods are achieved by applying sinusoidal force to the food over a range of frequencies and recording the corresponding displacement, acceleration or velocity (Fig. 5.11). Firmness is determined by analyzing the frequency spectrum of the ratio of force to deformation (or velocity or acceleration). Rohrbach and Glass (1980) determined the firmness of blueberries by measuring the mechanical impedance using a dynamic device. The mechanical impedance, the ratio of force to velocity in the frequency domain, was measured with a...


The drop test has been used to measure the firmness of a number of fruits and vegetables. Rohrbach (1981) developed a computer-controlled impact device that recorded the IFR of blueberries dropping 40 mm onto a rigid plate sensor. Seventy five percent of berries with firmness defects (soft berries) were correctly sorted into appropriate firmness grades by using C2 as a sorting criterion. Delwiche et al. (1987) studied the IFR of peaches apples, blueberries, apricots, blueberries, raspberries

Oranges and lemons

(1) A cell with a particular hidden colour gives off an associated scent. We can get an intuitive grasp of this rule because we commonly make associations between smells and colours. Orange, lemon, plum and strawberry are all colours, but they are also associated with particular scents the smells of oranges, lemons, plums and strawberries. It is not that the colour pigments in the fruits are directly responsible for the smell, but the two are associated with each other. An orange fruit is both coloured orange, due to its pigment molecules, and gives off a particular scent, because it produces other molecules that can enter the air and be detected by our nose. In the same way, each hidden colour is not directly responsible for the scent given off by a cell, but is associated with it. Each hidden colour is a master protein of a particular type, whereas each scent is a signalling protein of a particular type.