BACKGROUND

[0001] Fruit preparations, such as sauces, jams, marmalades, and jellies, are a way to add interest and flavor to foods, such as yogurt, bread, cottage cheese, or drinks. A fruit preparation is generally made by cooking whole fruit, pieces, puree, and/or juice, often with water and sugar, and optionally other ingredients, such as gelling agents, to produce the fruit preparation. The cooking process is often used to at least partially preserve the preparation, as well as to cause gelling of pectin from the fruit or gelling agents. Cooking also tends to cause softening or disintegration of the fruit, and causes changes in the flavor and/or aroma of the fruit.

SUMMARY

[0002] The present disclosure relates to methods of making a processed fruit and fruit compositions containing a processed fruit made by a disclosed method.

[0003] A method of processing a fruit is described herein. The method includes applying a pulsed electric field to a fruit to produce a perforated fruit, and infusing the perforated fruit with an infusion agent to produce a processed fruit. An infusion agent can include a firming agent, a flavoring agent, a coloring agent, an antimicrobial, an enzyme inhibitor, a probiotic, a prebiotic, a starter culture, or any combination thereof.

[0004] ln some embodiments, an electric field can be applied to fruit at an energy rate of from about 2.5 kV/cm to about 5 kV/cm, with a total energy input of about 1.4 kJ to about 5.5 kJ per kg of the fruit to produce a perforated fruit.

[0005] In some embodiments, a method of processing a fruit can include applying a pulsed electric field to a fruit at an energy rate of from about 2.5 kV/cm to about 5 kV/cm, with a total energy input of about 1.4 kJ to about 5.5 kJ per kg of the fruit to produce a perforated fruit, and infusing the perforated fruit with a firming agent to produce a processed fruit ln some embodiments, the perforated fruit can be infused with a firming agent and one or more additional infusion agent.

[0006] In some embodiments, a firming agent includes pectin methylesterase and a divalent cation. [0007] In some embodiments, a method of processing a fruit includes combining the perforated fruit with a sugar.

[0008] In some embodiments, a method of processing a fruit includes thermally treating the processed fruit to produce a thermally treated fruit. In some embodiments, the thermal treatment step includes heating the processed fruit with a sugar to produce a fruit preparation.

[0009] In some embodiments, a method of processing a fruit includes the fruit can be at least partially thawed from a frozen state prior to applying the pulsed electric field.

[0010] In some embodiments, a method of processing a fruit includes freezing or drying the processed fruit.

[0011] In some embodiments, a method of processing a fruit includes freezing the perforated fruit before infusing the perforated fruit with the infusion agent, such as a firming agent.

[0012] In some embodiments, a method of processing a fruit results in a processed fruit that has a substantially intact appearance.

[0013] In some embodiments, a fruit used in a method of processing a fruit can be a blueberry, honeysuckle berry, gooseberry, currant, cherry, pea, plum, date, or olive.

[0014] In some embodiments of a method provided herein, the processed fruit can have an altered appearance or flavor relative to the fruit.

[0015] In some embodiments of a method provided herein, the processed fruit can have an extended shelf life relative to the fruit.

[0016] In some embodiments of a method provided herein, the processed fruit can have an increased fiber content relative to the fruit.

[0017] A fruit composition is provided herein, where the fruit composition includes a perforated fruit infused with an infusion agent. An infusion agent can include a firming agent, a flavoring agent, a coloring agent, an antimicrobial, an enzyme inhibitor, a probiotic, a prebiotic, a starter culture, or any combination thereof.

[0018] In some embodiments, a fruit composition provided herein can include a perforated fruit infused with a firming agent and one or more additional infusion agent.

[0019] In some embodiments, a fruit composition can include a perforated fruit infused with pectin methylesterase and a divalent cation. [0020] In some embodiments, a fruit composition can further include one or more additional food ingredient. In some embodiments, the one or more additional food ingredient includes a sugar.

[0021] In some embodiments, the perforated fruit in a fruit composition provided herein can be frozen.

[0022] ln some embodiments, the perforated fruit in a fruit composition provided herein can be pasteurized.

[0023] In some embodiments, the perforated fruit in a fruit composition provided herein can be a blueberry, honeysuckle berry, gooseberry, currant, cherry, pea, plum, date, or olive.

[0024] In some embodiments, a perforated fruit in a fruit composition provided herein can have a substantially intact appearance

[0025] In some embodiments, a perforated fruit in a fruit composition can have an altered appearance or flavor relative to the original fruit.

[0026] In some embodiments, a perforated fruit in a fruit composition can have an extended shelf life relative to the original fruit.

[0027] In some embodiments, a perforated fruit in a fruit composition can have an increased fiber content relative to the original fruit.

[0028] These and various other features and advantages will be apparent from a reading of the following detailed description.

DRAWINGS

[0029] Figure 1 shows a force over distance profile observed while measuring firmness of fresh fruit (left) as compared to cooked fruit treated with sugar but no PEF (right).

[0030] Figure 2 shows a force over distance profile observed while measuring firmness of fresh fruit (left) as compared to cooked fruit treated PEF but no PME.

[0031] Figure 3 shows a force over distance profile observed while measuring firmness of fresh fruit (left) as compared to cooked fruit treated PEF plus sugar and PME.

[0032] Figure 4 shows a force over distance profile observed while measuring firmness of fresh fruit (left) as-compared to cooked fruit treated PEF plus sugar and PME.

[0033] Figure 5 shows taste perception by a trained panel of a fruit preparation made from frozen fruit that was not treated with PEF or a firming agent. Taste perception was measured for blueberry flavor, sour flavor, sweet flavor, and“other fruit” flavor at bite 1 , bite 2, bite 3, and after taste (AT).

[0034] Figure 6 shows taste perception by a trained panel of a fruit preparation made from frozen fruit that was treated with a firming agent but not treated with PEF. Taste perception was measured for blueberry flavor, sour flavor, sweet flavor, and“other fruit” flavor at bite 1 , bite 2, bite 3, and after taste (AT).

[0035] Figure 7 shows taste perception by a trained panel of a fruit preparation made from frozen fruit that was treated with PEF at about 5 kJ/kg and a firming agent. Taste perception was measured for blueberry flavor, sour flavor, sweet flavor, and“other fruit” flavor at bite 1, bite 2, bite 3, and after taste (AT).

[0036] Figure 8 shows taste perception by a trained panel of a fruit preparation made from frozen fruit that was treated with PEF at about 2.5 kJ/kg and a firming agent. Taste perception was measured for blueberry flavor, sour flavor, sweet flavor, and“other fruit” flavor at bite 1 , bite 2, bite 3, and after taste (AT).

DETAILED DESCRIPTION

[0037] Consumers are increasingly looking for eating experiences that more closely resemble fresh food or less processed foods. It can be difficult, however, to balance the desire of consumers to experience foods that more closely resemble fresh food with food safety. For example, fruit preparations are heated or cooked to at least partially preserve the fruit from microbial and enzymatic degradation, but heating and cooking changes the texture and flavor of the fruit in the preparation such that the fruit is noticeably different from fresh. In some types of fruit, the heating or cooking process results in significant structural disintegration of the fruit ln some cases, disintegration can be reduced by applying a firming agent, such as pectin methylesterase, to the fruit before cooking to result in larger and/or firmer pieces that are more recognizable to the consumer.

[0038] However, the present application discloses how the use of a firming agent doesn’t work on whole fruit with a tough skin, such as blueberries. It was determined that the skin is a barrier to penetration of the fruit by a firming agent. While this problem could be solved by cutting the fruit or shaving at least a portion of the skin off of the fruit, such solutions resulted in an undesirable appearance. [0039] It was discovered, and is disclosed herein, that a pulsed electric field (PEF) can be used to perforate skin on a fruit to allow infusion of the fruit while maintaining a substantially intact appearance of the fruit. In particular, it was discovered that PEF, with a relatively low energy rate and a relatively low total energy input, was sufficient to perforate the skin of fruit without causing the fruit structure to disintegrate. Perforated fruit could then be infused with a number of compositions, such as a firming agent. A perforated fruit infused with a firming agent provided herein can have a texture, once thermally treated, that is firmer than a thermally treated fruit that is not perforated and infused with a firming agent. Further, in some embodiments, a perforated fruit infused with a firming agent provided herein can have a flavor that more closely resembles uncooked fruit as compared a thermally treated fruit that is not perforated and infused with a firming agent.

[0040] Although PEF has been used for non-thermal anti-microbial treatment of liquid foods, disintegration of larger pieces of food into smaller pieces, and facilitating juice or oil extraction from fruits, it was not known that PEF could be used on whole fruit or large fruit pieces without causing the fruit structure to disintegrate. In addition, while PEF was known to be useful for facilitating transfer of small molecules into cells, there was no indication that mass transfer could be applied to whole fruits or larger fruit pieces with any effectiveness beyond the cell membrane level without causing significant structural damage to the fruit.

[0041] As used herein,“pulsed electric field” or“PEF” refers to application of brief pulses (microseconds to milliseconds per pulse) of an electric field to a fruit placed between a set of electrodes. As used herein, the strength of the electric field is the“energy rate”, and is measured in kilovolts per centimeter (kV/cm). As used herein, the“total energy input” is the total amount of energy applied to fruit as measured in kilojoules energy per kilogram fruit (kJ/kg).

[0042] As used herein, the term“fruit” refers to an edible plant part, including fruit or vegetable, that has a skin on at least a portion of the plant part. Fruit, as described herein, includes berries (e.g., blueberries, gooseberries, cranberries, redcurrants, blackcurrants, whitecurrants, honeysuckle, raspberries, blackberries, and the like), cherries, grapes, olives, tomatoes, rhubarb, peas, plums, dates, cucumbers, beans, and the like. In some embodiments, a fruit can be intact, with no apparent cuts or breaches in the skin of the fruit.

[0043] A method of processing a fruit is provided herein. A method includes applying a PEF to a fruit at an energy rate and energy input sufficient to produce microscopic perforations in the skin of the fruit without causing the fruit structure to disintegrate to produce a perforated fruit. For example, an energy rate of from about 2.5 kV/cm to about 5 kV/cm (e.g., from about 2.5 to about 4 kV/cm, or from about 2.5 to about 3.5 kV/cm), with a total energy input of about 1.4 kJ to about 5.5 kJ (e.g., from about 1.4 to about 3 kJ, or from about 2 to about 3 kJ) per kg of fruit can be used. For blueberries, an energy rate of from 2.75 to about 3.5 kV/cm, with a total energy input of about 2 to about 3 kJ per kg of blueberries is particularly useful for producing perforated blueberries.

[0044] In some embodiments, a fruit suitable for use in a method of processing a fruit can be fresh prior to applying a PEF. In some embodiments, a fruit suitable for use in a method of processing a fruit can be preserved prior to applying a PEF. For example, a fruit can be frozen prior to applying a PEF. Preferably, a fruit that has been frozen prior to applying a PEF is thawed sufficiently to allow electric current to be conducted through at least the skin of the fruit. In some embodiments, a fruit can be dried prior to applying a PEF. A fruit that is dried prior to applying a PEF should have sufficient moisture to allow electric current to be conducted through at least the skin of the fruit.

[0045] Following PEF treatment, a perforated fruit provided herein can be further processed to produce a processed fruit. In some embodiments, a perforated fruit can be infused with an infusion agent. As used herein, the term“infusion agent” is a composition that can be applied to a perforated fruit that can enter the microscopic openings in the skin of the fruit. Suitable infusion agents can include firming agents (e.g., pectin methylesterase/divalent cations, sugar, pectins, gums, hydrocolloids, or combinations thereof), flavoring agents (e.g., sugar, honey, natural flavorants, artificial flavorants, and the like), coloring agents (e.g., natural colorants, artificial colorants, and the like), antimicrobials (e.g., organic acids, plant extracts, and the like), probiotics (e.g., lactic acid bacteria), prebiotics (e.g., soluble fibers, insoluble fibers, and the like), starter cultures (e.g., fermentation bacteria, fermentation yeasts, and the like), anti-browning agents (e.g., organic acids, salts, enzyme inhibitors, and the like) and combinations thereof. Infusion, as described herein, can be performed using any appropriate method, including soaking of perforated fruit in a solution containing an infusion agent, spraying perforated fruit with a solution containing an infusion agent, vacuum infusion, and the like. In some embodiments, infusion can be performed during PEF treatment by including an infusion agent with the fruit during PEF treatment. [0046] A firming agent applied to a perforated fruit, such as sugar and/or pectin methylesterase (PME) and a divalent cation, can increase firmness of the perforated fruit. In some embodiments, a firming agent can increase firmness of the fruit and/or appearance of more intact fruit (e.g., larger pieces or substantially intact fruit) after thermally processing the perforated fruit as compared to a thermally processed fruit that has not been infused with a firming agent. For example, a blueberry fruit preparation (e.g., a sauce or jam) made with whole blueberries that have not been infused with a firming agent often results in a fruit preparation that has few or no intact blueberries, or blueberries that are significantly softer than fresh blueberries. In contrast, a blueberry fruit preparation made with whole blueberries infused with a firming agent can have blueberries that are firmer or more intact relative to a blueberry fruit preparation that is made from blueberries that have not been infused.

[0047] As used herein,“firmness” of a fruit is measured by measuring the force required to push a blade through the fruit. For example, firmness can be measured by measuring the force required to press blades of a Kramer Type Shear Cell through fruit in the Kramer Type Shear Cell. Firmness can be measured as peak force in Newtons or kilograms. See Tables 2 and 4, below.

[0048] In some embodiments, a firming agent applied to a perforated fruit, such as sugar and/or pectin methylesterase (PME) and a divalent cation, can cause perceived texture of the perforated fruit to more closely resemble perceived texture of a fresh fruit. As used herein, “perceived texture” refers to how a person experiences the texture of a fruit upon chewing the fruit. Perceived texture can be associated with a force over distance profile observed while measuring firmness of a fruit, as described above. See, e.g., Figures 1 -4. A perforated fruit having a perceived firmness resembling a fresh fruit can have a force over distance profile that is similar to the force over distance profile of the fresh fruit. For example, a fresh blueberry can have a force over distance profile that shows an increase in measured force over about 0 mm to about 20-30 mm, followed by a relative plateau in measured force from about 20-30 mm to about 40-45 mm, followed by a decrease in measured force after about 40-45 mm. See the graphs on the left of Figures 1-4. A perforated blueberry that has been treated with a firming agent (e.g., PME/CaC12) then cooked, and has a perceived texture resembling the fresh blueberry described above, can have a force over distance profile that shows an increase in measured force over about 0 mm to about 20-30 mm, followed by a relative plateau in measured force from about 20-30 mm to about 40-45 mm, with or without a peak in force at about 40-45 mm, followed by a decrease in measured force after about 40-45 mm. See the graphs on the right of Figures 2-4, particularly with respect to Figures 3 and 4. In contrast, a blueberry that has not been perforated but has been cooked does not have a perceived texture resembling the fresh blueberry described above, and has a force over distance profile that does not show a plateau at about 20-30 mm to about 40-45 mm. See the graph on the left of Figure 1.

[0049] In some embodiments, a firming agent can increase perception of a fresh fruit flavor in a thermally treated fruit preparation relative to a thermally treated fruit preparation made from fruit that has not been infused with a firming agent.

[0050] In some embodiments a perforated fruit provided herein can be infused with a starter culture. Suitable starter cultured can include fermentation microorganisms (e.g., bacteria or yeast), or probiotic microorganisms. In some embodiments, a perforated fruit can be packaged and sold in refrigerated or frozen form to consumers. Consumers can purchase fruit infused with a starter culture to produce their own fermented foods. For example, a fruit infused with a starter culture can be submerged in water or an aqueous solution at room temperature or refrigerated conditions for several hours to several days to produce a whole fermented fruit. Whole fermented fruit can provide an enjoyable snack, as such fermented fruit is often perceived as having a sparkling or effervescent flavor. In another example, a fruit infused with a starter culture can be used to make wine or other fermented beverage without requiring separate addition of a starter culture.

[0051] In some embodiments, an infusion agent such as a flavoring agent or a coloring agent can change the appearance and/or flavor of a processed fruit relative to the original fruit. For example, a blueberry can be infused with a lemon flavor to produce a blueberry that tastes like a combination of blueberry and lemon. In another example, a cherry can be infused with a blue colorant to make the cherry appear blue.

[0052] In some embodiments, an infusion agent can provide a nutritional benefit. For example, a perforated fruit provided herein can be infused with a probiotic, a prebiotic, a vitamin, a mineral, a fiber, or the like.

[0053] In some embodiments, an infusion agent, such as an antimicrobial agent (e.g., citric acid, lactic acid, vanillin, eugenol, potassium sorbate, calcium propionate, nisin, and the like), can be used to improve shelf life and/or reduce microbial load of a processed fruit. [0054] In some embodiments, an infusion agent, such as an anti-browning agent or an enzyme inhibitor (e.g., ascorbic acid, 4-hexylresorcinol, sodium chloride, proteases, and the like), can be used to improve shelf life, texture, flavor, and/or appearance of a processed fruit.

[0055] In some embodiments, perforated fruit can be infused with any combination of one or more infusion agent. For example, a firming agent can be combined with one or more other infusion agents in order to maintain fruit firmness. In another example, a perforated fruit can be infused with a prebiotic and a probiotic.

[0056] The amount of an infusion agent used to infuse a perforated fruit can be adjusted as needed to provide the desired level of infusion. For example, perforated blueberries can be infused with PME and a divalent cation by contacting the perforated fruit with PME and divalent cation, either as a powder or a solution, at an amount of from about 0.1% to about 5% (e.g., from about 0.1% to about 3%, or from about 0.2% to about 3%) of each of PME and divalent cation by weight of the fruit. In some embodiments, a lower concentration solution of an infusion agent may be more suitable for application by soaking, while a higher

concentration solution of an infusion agent may be more suitable for application by spraying. In another embodiment, perforated fruit can be packed with powdered PME and divalent cation such that moisture from the fruit can allow dissolution of the PME and divalent cation, and entry into the perforated fruit.

[0057] In some embodiments, a perforated fruit provided herein can be further processed by freezing. In some embodiments, a perforated fruit can be frozen after PEF treatment but before infusion. Freezing a perforated fruit can be useful for storage prior to infusion. In some embodiments, a frozen perforated fruit can be packaged and sold to a consumer for later infusion by the consumer.

[0058] in some embodiments, a perforated fruit can be frozen following infusion. For example, a perforated fruit infused with a firming agent can be frozen for later thermal processing by a manufacturer or it can be packaged for sale to a consumer.

[0059] A frozen perforated fruit can be stored with other ingredients. For example, a frozen perforated fruit, either infused or non-infused, can be packed with granular sugar during frozen storage. In another example, a frozen perforated fruit can be stored frozen with an infusion agent such that the infusion agent infuses the fruit upon thawing of the frozen perforated fruit. [0060] In some embodiments, a perforated fruit provided herein can be further processed with a thermal treatment. In some embodiments, a thermal treatment step can be sufficient to pasteurize the perforated fruit.

[0061] In some embodiments, a perforated fruit infused with a firming agent can be thermally treated with one or more additional food ingredients. For example, a perforated fruit can be infused with a firming agent and then cooked with sugar and/or other food ingredients (e.g., water, citric acid, lactic acid, and/or viscosity modifiers, such as starch or gelatin) to produce a fruit preparation. An example of a fruit preparation formula is provided below.

Fruit Preparation Formula Example

[0062] In some embodiments, a perforated fruit provided herein can be dried following perforation or infusion. For example, a perforated fruit infused with a probiotic can be dried and packaged for sale.

[0063] A perforated fruit, an infused perforated fruit, or a fruit composition including a perforated fruit or infused perforated fruit (e.g., a fruit preparation) provided herein can be produced using any suitable equipment. For example, PEF treatment can be performed using batch PEF equipment, such as elea ® PEFPILOT™, or continuous PEF equipment, such as elea ® SMOOTHCUT™ continuous PEF machine. In another example, thermal treatment can be performed using a batch cooker, or in a continuous mode using, for example, a standard tubular heat exchanger for viscous and particulate food, such as commercial designs by Tetra Pak® (Rockford, IL, USA) or JBT FoodTech (Chicago, IL, USA). Thermal treatment can be done using any appropriate method, such as steam injection, hot oil or steam jacketed heating, microwave heating, or ohmic heating. [0064] A perforated fruit, an infused perforated fruit, or a fruit composition including a perforated fruit or infused perforated fruit can be packaged in any appropriate packaging for storage and/or sale. For example, a fruit preparation provided herein can be packaged in 5 gallon buckets or other rigid packaging, or in 500 kg industrial totes or other flexible packaging. In another example, a fruit preparation provided herein can be packaged with another food product, such as a yogurt, ice cream, or the like, in the same or separate containers. In another example, a perforated fruit infused with a starter culture can be packaged in a glass or plastic container suitable for performing fermentation.

EXAMPLES

Example 1

[0065] Experiments were performed to improve blueberry texture after cooking. Whole or halved blueberries were treated according to Table 1. For blueberries that were treated with a freeze/thaw treatment, fresh blueberries were blended with PME (1 g/500 g fruit), CaC12 (1 g/500 g fruit), and sugar (1 g/7 g fruit), or just sugar (1 g/7 g fruit), then frozen and thawed before cooking. For blueberries that were treated with vacuum infusion, fresh blueberries were vacuum infused in water (1000 g/500 g fruit) containing PME (1 g/100 g water) and CaC12 (1 g/100 g water) at -15 inches Hg for 5 minutes, followed by a hold time of 5 minutes before cooking. Blueberries were cooked over steam until reaching an internal temperature of 170° F. Whole or halved blueberries that were uncooked from fresh with no additional treatment were used as a control. Firmness was measured using a TA.XT Plus Texture Analyzer (Texture Technologies, Hamilton, A, USA) fitted with a 5 kg load cell and a test speed of 2 mm/sec. Approximately 10 to 12 g of blueberries was placed in a mini-Kramer shear cell (Stable Micro Systems, Surrey, United Kingdom). Firmness was measured as the average area in kg of force between the curve and a 10 g baseline up to a peak force over 3 repetitions, and is shown in Table 1. Table 1

[0066] The results of this experiment show that only blueberries that were halved showed significant improvement in firmness following PME infusion, and moderate improvement in firmness when packed with sugar alone. Improvement in firmness could also be observed in blueberries that had a section of skin shaved from the surface. A freeze/thaw cycle on whole blueberries was not sufficient to improve texture of blueberries treated with PME, nor did vacuum infusion on whole blueberries with PME improve texture. This suggests that one or both of PME and CaC12 were not able to pass through the skin of intact blueberries.

Example 2

[0067] Experiments were performed to determine if pulsed electric field (PEF) treatment could be used to improve infusion of PME. Fresh whole blueberries were washed, drained, and weighed into a 1 10 cm ³ PEF treatment chamber for use in an elea ® batch PEF apparatus (elea GmBH, Quakenbruck, Germany). The blueberries were submerged in 20° C tap water in the PEF chamber, and a pulsed electric field was applied between plates separated by 30 mm at a frequency of 1 Hz. Four Treatment Groups (Treatment Group I-IV) were treated with a field strength (FS) of 1 kV/cm or 3 kV/cm, and up to 235 pulses (PC), to result in a specific energy input (SEI) ranging from about 1 to about 5 kJ/Kg, as indicated in Table 2. In preliminary experiments, this field strength and energy input was found to decrease firmness of blueberries if no firming agent was applied.

[0068] In this experiment, after PEF treatment, the perforated blueberries were sprayed with a PME/CaC12 solution using a spray bottle. The PME/CaC12 solution contained either 2.4 g each of PME and CaC12 per 24 g water (Solution A), or 7.2 g each of PME and CaC12 per 24 g water (Solution B). The sprayed blueberries were then blended with granular sugar, transferred into sealed plastic containers and stored for 2 to 4 days at -18° C. Frozen blueberries were then thawed at 2° C, followed by thermal treatment using a steam cooker until the core temperature of the berries reached 92° C. Thermally treated blueberries were immediately placed in an ice bath to cool prior to texture analysis. In addition to

PEF/PME/CaC12 treated blueberries, three control groups were also tested. Control 1 included blueberries that were not treated with PEF or PME/CaC12, and were frozen and thermally treated as described above. Control2 included blueberries that were PEF treated, but not treated with PME/CaC12, and were frozen and thermally treated as above. ControB included blueberries that were not treated with PEF, but were treated with PME/CaC12, and were frozen and thermally treated as above. A fresh blueberry control was not treated with PEF or PME/CaC12, and was not frozen or thermally treated.

[0069] Firmness analysis was performed using a Zwick material testing machine model 1445 (Zwock GmbH & Co.KG, Ulm, Germany) equipped with a Kramer shear cell system. The Kramer shear cell was filled with blueberries at a temperature of about 10° C to 50% of the Kramer shear cell’s volume. The weight of the blueberries was noted and the texture analysis was performed using the following settings: pre-test distance = 0.5 m; test distance = 55 mm; test speed = 2 mm/s. Momentary force was recorded as a function of test distance during travel of the shear blade assembly into the sample. The results are shown in Table 2. For the purposes of comparison, the lot of fresh blueberries in Treatment Group 1 were also used in Treatment Group II, while the lot of fresh blueberries from Treatment Group III were also used in Treatment Group IV.

Table 2

[0070] The results showed that cooked blueberries that are not treated with PEF had lower firmness compared to fresh blueberries. Blueberries treated with PEF and sugar regained some firmness, and blueberries treated with PEF and a PME/CaC12 were firmer than PEF + sugar in most cases. In a similar experiment, tasting results showed that blueberries treated with PEF at a field strength of 3.0 kV/cm and treated with PME had a perceived texture closest to fresh. Interestingly, while PME/CaC12 improved the firmness of ControB in Treatment Group I, it did not provide a similar eating experience to fresh.

[0071] However, it was observed that samples that more closely resembled fresh blueberries with respect to perceived texture showed an early rise in force over distance (e.g., by 30 mm), followed by a relative plateau in force over distance (e.g., from about 30 mm to about 40 mm), and then a peak in force. Figures 1 -4 show examples of force-distance graph profiles. Generally, the samples that most closely resembled fresh blueberries had a force- distance graph profile that resembled the force-distance graph profile in the respective fresh blueberry sample with the addition of a more prominent peak than in fresh before the force drops significantly. See Figures 3 and 4, comparing PME treated samples with fresh. Also, PEF at a field strength of 3 kV/cm and no PME provided some similarity to fresh, though to a lesser extent. This may be attributable to osmotic effect on the perforated blueberries when they are soaked in the ice bath. See Figure 2. In comparison, samples that least closely resembled fresh blueberries with respect to perceived texture showed little to no rise in force over distance before a sharp peak. See Figure 1, comparing cooked blueberries treated with sugar but no PEF (Control 1 from Group IV in Table 2 on right) with fresh blueberries (left). It is to be understood that the rate and degree of rise in force over distance may vary based on the variety, freshness, and type of fresh fruit used.

Example 3

[0072] Experiments were performed to determine if pulsed electric field (PEF) treatment plus infusion with a firming agent could improve perception of whole berries in a fruit preparation. For PEF, fresh whole blueberries were washed, drained, and weighed into the same model PEF chamber as used in Example 2. The blueberries were submerged in 20° C tap water in the PEF chamber, and a pulsed electric field was applied between plates separated by 30 mm at a frequency of 1 Hz. Samples treated with PME were either treated with Blend A (2 g each of PME and CaC12 in 20 g water) or Blend B (6 g each of PME and CaC12 in 20 g water). Treatments were as indicated in Table 3. For each treatment condition, multiple small batches (each batch about 350 g blueberries with 400 g water) were pooled and mixed to achieve at least 1500 g of blueberries to be treated with the indicated firming agent.

Table 3

[0073] All samples were frozen for at least 3 months as bulk, sugar-packed fruit, a format frequently used by the frozen fruit industry for long term storage of fruit. After 3 months, the frozen fruit was thawed in tap water. Firmness of the thawed berries was measured using a TA-XTP/ws texture analyzer (Texture Technologies, Hamilton, MA, USA) equipped with a Miniature Kramer shear cell system (Stable Micro Systems, Surrey, United Kingdom). The Miniature Kramer shear cell was filled with blueberries at a temperature of about 10° C up to 50% of the Kramer shear cell’s volume (about 50 g of fruit preparation). The weight of the blueberries was noted and the texture analysis was performed using the following settings: pre-test speed = 5 mm/sec; test distance = 25 mm; test speed = 2 mm/s. Momentary force was recorded as a function of test distance during travel of the shear blade assembly into the sample. Each sample was then made into a fruit preparation by combining berries with sugar, water, and other minor ingredients, then cooked. Following cooking, the fruit preparation was pasteurized for 10 minutes at 85° C, then statically cooled to 10° C. Blueberries from the fruit preparation were removed from the fruit preparation, rinsed, and the firmness measured as described for the thawed blueberries. The results are shown in Table 4. Table 4

[0074] The fruit preparations were submitted to a trained sensory panel for descriptive analysis. Taste perception was measured for blueberry flavor, sour flavor, sweet flavor, and “other fruit” flavor at bite 1, bite 2, bite 3, and after taste (AT). Samples from Treatment 1 and 2 had a firmer texture than either control. Treatment 1 (Figure 7) and 2 (Figure 8) also had a higher score for blueberry flavor as compared to either Control 1 (Figure 5) or Control 2 (Figure 6), with each of the Treatment groups having a blueberry flavor score around 3 over 3 bites, while the controls had a blueberry flavor score around 2 for 3 bites.

Example 4

[0075] Experiments were performed on frozen and thawed fruit to determine whether PEF could be applied to previously frozen fruit. The results showed that PEF could be performed on frozen and at least partially thawed fruit to enable successful infusion with an infusion agent. Tests showed that previously frozen fruit could be thawed, treated with PEF and a firming agent to get similar results to Examples 2 and 3 with regard to firmness and perceived texture.

Example 5

[0076] Experiments were performed on grapes and tomatoes to determine whether PEF could be used on these fruits to facilitate infusion with an infusion agent. Briefly, grapes and cherry tomatoes were treated with PEF at a field strength of 2.9 kV/cm with sufficient pulses to achieve a total energy that ranged from 1.406 kJ/kg to 7.369 kJ/kg, as shown in Table 5. Following PEF treatment, samples were treated with PME and CaC12, then frozen for 2 weeks. Upon thawing, the samples were cooked over steam to an internal temperature of at least 95° C maintained for 3 minutes. The results showed that PEF could be used to infuse grapes and cherry tomatoes with a firming agent similarly to blueberries. The cherry tomato results showed that PME/CaC12 could be used to firm tomatoes similarly across all of the tested PEF total energy inputs. The grape results showed less consistent results than the blueberries and cherry tomatoes, likely due to lower levels of pectin in grapes available for cross linking using PME. It is expected that optimization of the firming agent and level of PEF energy input would be desired for each botanical source.

Table 5

[0077] The implementations described above and other implementations are within the scope of the following claims. One skilled in the art will appreciate that the present disclosure can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation.