The effect of the pre-treatments and the long and short-term frozen storage on the quality of raspberry (cv. Heritage)

Results are presented of the effect of pre-treatments before freezing followed by long and short-term frozen storage (12 months at –18 °C and 24 days suffering temperature fluctuations between –18 °C and –12 °C) on quality parameters of raspberry. Pre-treatments were carried out with calcium, low methoxyl pectin, a combined solution, and results compared with untreated control fruits. Kramer shear, back extrusion, compression, and multiple penetration tests were used to measure rheological behavior. One-hundred mM CaCl₂ reduced the long and short-term frozen storage induced loss of firmness. For long-term storage at –18 °C, a softening of the tissue became evident between 3 and 12 months and at each date test the stored fruits were firmer than those without storage. For short-term storage with fluctuations, the loss of firmness was evident between 0 and 24 days, and at all the testing dates the stored fruits were softer than those without storage. Results evidenced a higher cell damage in the short-term frozen storage. Coefficients of softening per day suffering fluctuation were determined, the highest values being given by Kramer shear energy and back extrusion maximum force (>1%). Short-term frozen storage affected physical and physico-chemical characteristics, increasing the saturation (r) and the anthocyanins and decreasing the ascorbic acid of the raspberries. In both storage conditions, pre-treatments reduced the drip loss, which correlated best with the Kramer shear energy. Panelists detected mainly time effect on the sensory firmness. For long-term, sensory firmness and juiciness gave the highest correlations with back extrusion maximum force, while for the short-term, sensory firmness and drip loss gave the highest correlations with the Kramer shear energy. SEM revealed different degrees of mechanical damage to structure, which accounted for rheological behavior of the fruits.     

Effect of modified starch concentration and freezing and thawing rates on properties of mashed potatoes (cv. Kennebec)

Effects of modified cornstarch concentration, freezing rate and thawing mode on quality properties of mashed potatoes were examined. The product was tested by oscillatory rheometry, instrumental texture profile analysis (ITPA) and cone penetration, colour, dry matter (DM) and sensory analyses. Oscillatory parameters showed that increasing starch concentration resulted in a softer product in which gel strength decreased in direct proportion to concentration in quick‐frozen and microwave‐thawed product. Quick freezing made for firmer mashed potatoes, whereas oscillatory, ITPA and penetration parameters were lower in the samples thawed at 4 °C. Starch concentration and instrumental consistency and firmness were directly proportional to one another. Adding starch at the highest concentration, quick freezing and slow thawing produced a lighter‐coloured mashed potato, although the loss of colour in the processed product was not detected by panellists in the microwave‐thawed samples. DM was higher in the quick‐frozen samples and lower in air‐thawed samples. The factors studied affected different sensory texture parameters but had hardly any effect on attributes perceived during final and residual phases of mastication. Only starch concentration had a significant effect on sensory acceptability, but interactions between factors showed that starch addition followed by quick freezing was judged undesirable by the panellists due to excessive softening. Oscillatory parameters correlated well with sensory texture attributes and proved quite precise. They would therefore appear to be the best test to monitor properties of frozen mashed potatoes. Copyright © 2007 Society of Chemical Industry     

Freezing, thawing and cooking effects on quality profile assessment of green beans (cv. Win)

Results are presented of the effect of freezing followed by thawing (air and water immersion, both at environmental temperature) and cooking (traditional boiling in a covered pot) on quality profile (in terms of objective texture, colour, chlorophylls and pheophytins and sensory attributes) and structure of green beans (cv. Win). Freezing was carried out at three different rates by forced convection with liquid nitrogen vapour. Kramer shear cell (KSC) and Warner–Bratzler (WB) tests were used for objective assessment of the texture. The highest parameter values occurred in beans frozen at the highest rate and air-thawed at the slowest rate. Also, minimum alteration of the rheological behaviour of cooked beans was achieved by freezing at the highest rate. The best parameter for assessing the texture of frozen green beans after thawing and cooking was the Warner–Bratzler slope (S _WB). Coefficients of softening estimated for S _WB in the thawed beans showed that the texture of the beans frozen at −24 °C was almost four and almost five times softer than that of the beans frozen at −70 °C, for air and water thawing respectively. Frozen and thawed green beans were darker than fresh control, whereas freezing prior to cooking produced lighter-coloured beans than direct cooking. The freezing rate affected colour parameters differently depending on the process that followed. When beans were thawed, increasing the freezing rate produced lighter-coloured beans, whereas when beans were cooked, increasing the rate produced darker-coloured beans. No difference was found in sensory assessments between cooked samples frozen at −24 °C, −35 °C and −70 °C, which probably reflects the panellists' mixed preferences for quickly and slowly frozen samples. Scanning electron microscopy (SEM) revealed different degrees of mechanical damage to tissue structure, which accounted for the rheological behaviour of the beans.     

Preservation of hermaphrodite and female papaya fruits (Carica papaya L ., Cv Sunrise, Solo group) by freezing: physical, physico-chemical and sensorial aspects

The physical, physico-chemical and sensorial changes that occur during the freezing and frozen storage of hermaphrodite and female papaya slices (Carica papaya L., cv Sunrise, Solo group) were studied. Samples were evaluated by panellists throughout a 1-year period of storage at –24°C; the panellists described the fruit in terms of physico-chemical measurements of texture (firnmess and total pectins content), colour [L, a _L , b _L , peroxidase (POD) and polyphenoloxidase (PPO) activities] and flavour/taste [soluble solids content, pH, tritatable acidity and quality index (^oBrix/acidity)], and ranked them in order of preference. Desserts prepared from frozen slices of hermaphrodite and female papaya fruits mixed with orange, lemon and sugar were also evaluated. The freezing process itself did not result in significant changes in the more commonly assessed quality parameters of texture, colour and flavour/taste. However, during storage at –24°C, changes in sensorial characteristics occurred that became more evident as storage continued (≤ 9 months). Nevertheless, these quality changes can be masked by using these papaya slices as an ingredient in fruit products, with frozen female papaya slices being especially suitable for this purpose.     

Effect of temperature, pressure and calcium soaking pre-treatments and pressure shift freezing on the texture and texture evolution of frozen green bell peppers (Capsicum annuum)

The firmness of green bell pepper (Capsicum annuum) was studied under different processing conditions. Thermal texture degradation kinetics of pepper tissue between 75 and 95 °C could be accurately described by a fractional conversion model. The firmness of pre-processed pepper increased when the samples were submitted to several heat, pressure, and combinations of heat/pressure and calcium soaking pre-treatments. Pre-heating at 55 °C during 60 min and mild heat/high-pressure treatments (200 MPa at 25 °C, 15 min) yielded the best results, which were further improved when combined with calcium soaking. These pre-treatments significantly slowed down thermal texture degradation of pepper at 90 °C, a typical temperature used for pepper blanching prior to freezing. The above-mentioned pre-treated samples showed a significant reduction in firmness when frozen by regular freezing at 0.1 MPa. The same samples showed no changes in firmness when frozen by high-pressure shift freezing at 200 MPa. When freezing was carried out by high-pressure shift and after frozen storage (−18 °C) for 2.5 months, pressure pre-treated pepper showed a better retention of texture than thermal pre-treated pepper.     

Preservation of hermaphrodite and female papaya fruits (Carica papaya L?., Cv Sunrise, Solo group) by freezing: physical, physico-chemical and sensorial aspects

 The physical, physico-chemical and sensorial changes that occur during the freezing and frozen storage of hermaphrodite and female papaya slices (Carica papaya L., cv Sunrise, Solo group) were studied. Samples were evaluated by panellists throughout a 1-year period of storage at –24°C; the panellists described the fruit in terms of physico-chemical measurements of texture (firnmess and total pectins content), colour [L, a _L , b _L , peroxidase (POD) and polyphenoloxidase (PPO) activities] and flavour/taste [soluble solids content, pH, tritatable acidity and quality index (^oBrix/acidity)], and ranked them in order of preference. Desserts prepared from frozen slices of hermaphrodite and female papaya fruits mixed with orange, lemon and sugar were also evaluated. The freezing process itself did not result in significant changes in the more commonly assessed quality parameters of texture, colour and flavour/taste. However, during storage at –24°C, changes in sensorial characteristics occurred that became more evident as storage continued (≤ 9 months). Nevertheless, these quality changes can be masked by using these papaya slices as an ingredient in fruit products, with frozen female papaya slices being especially suitable for this purpose. Received: 1 August 1997 / Revised version: 14 November 1997     

Relation between bioactive compounds and free radical‐scavenging capacity in berry fruits during frozen storage

In this work the correlation between the free radical‐scavenging capacity and bioactive compounds (anthocyanins, ellagic acid, total phenolics and vitamin C) in four Spanish raspberry cultivars (Heritage, Autumn Bliss, Zeva and Rubi) and Spanish wild blackberry as affected by freezing and frozen storage was evaluated. From this mathematical study a significant correlation was obtained between the radical‐scavenging capacity and the anthocyanin and total phenolic contents in both raspberry (r = 0.85 and 0.83 respectively) and blackberry (r = 0.84 and 0.68 respectively) fruits, but no correlation was found between this parameter and the ellagic acid and vitamin C contents. A key objective of this study was to select the raspberry cultivar most suitable for freezing preservation in terms of the stability of its health‐promoting constituents. A two‐dimensional principal component analysis (PCA) of the raspberry cultivars explained 82% of the total variance of the factors mentioned above. The early raspberry cultivars (Heritage and Autumn Bliss) showed a lower content of bioactive compounds and lower radical‐scavenging capacity, while the late cultivars (Zeva and Rubi) showed higher values, and these differences were clearly displayed by the PCA. © 2003 Society of Chemical Industry     

Chemical pretreatments and partial dehydration of ash gourd (Benincasa hispida) pieces for preservation of its quality attributes

Ash gourd (Benincasa hispida) is a commonly consumed vegetable in Asian subcontinent. Cut ash gourd pieces undergo severe decay within two days probably due to physical, biochemical and microbiological activities. Ash gourd pieces were chemically pretreated with sodium salt of ethylene diamine tetra acetic acid (sodium EDTA), calcium chloride (CaCl₂), citric acid and potassium metabisulphite (KMS) and dehydrated up to 30 percent moisture with an aim to extend its shelf life. Storage study of these samples was done with respect to texture, colour, bacterial content and water holding capacity. Shelf life was extended from two days to one month. Pretreatment using a combination of 1 mM EDTA, 2.5 percent KMS, 0.5 percent citric acid and 2.5 percent CaCl₂ and partial dehydration to 30 percent moisture found to be a good method in preservation of cut ash gourd pieces.     

A survey of ellagitannin content in raspberry and blackberry cultivars grown in Trentino (Italy)

This study describes the first application of a new procedure for acid hydrolysis of Rubus ellagitannins in methanol, which allows quantification of all the major reaction products (ellagic acid, methyl-sanguisorboate, methyl gallate and an unknown ellagic acid derivative) and estimation of the mean degree of polymerization (mDP) of Rubus ellagitannins. The ellagitannins of 21 raspberry and 15 blackberry cultivars produced in Trentino, Italy during 2005 were extracted and characterised. The total content of ellagitannins was shown to vary by a factor of 2 among raspberry cultivars and by a factor of 4 among blackberry cultivars.     

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

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

The effect of calcium on microbial quality and consistency of chile pepper (Capsicum annuum cv. Mesilla Cayenne) mash during fermentation

The fermentation of chile peppers (Capsicum annuum cv. Mesilla Cayenne) is dependent on several factors: temperature, acidity, salt concentration, dissolved air, microbial flora, carbohydrate and enzymes. This study measured the effect of two levels (8 or 15 g/100 g) of calcium citrate (CaCit, [Ca₃(C₆H₅O₇)₂]), calcium chloride (CaCl₂) or sodium chloride (NaCl) added to 24 h after pepper was mashed. Viscosity, pH, alcohol, soluble solids and microbial contamination were measured at day 1 and day 21 of fermentation. After 21 days of fermentation the Ca Cit 15 and CaCl₂ 8 treatments improved viscosity compared to control (P?0.05), but were not different from other calcium treatments or NaCl 15. The addition of calcium in the form of CaCl₂ at 8 or 15 g/100 g affected the fermentation of pepper mash by releasing more soluble sugars, increasing alcohol and reducing pH compared to control or other treatments. Also CaCl₂ treatments were effective in controlling microbial growth. Further studies are needed to evaluate color, texture, consistency and flavor of the combination of 8 g/100 g NaCl and 0.04 g/100 g CaCl₂ added to cayenne pepper mash to assess the value in an industrial setting.The effect of calcium on microbial quality and consistency of chile pepper (Capsicum annuum cv. Mesilla Cayenne) mash during fermentation.     

Flavonoid glycosides and antioxidant capacity of various blackberry,blueberry and red grape genotypes determined by high‐performance liquid chromatography/mass spectrometry

Anthocyanin and flavonol glycosides of various blackberry, blueberry and red wine grape genotypes were identified and measured by a high‐performance liquid chromatographic (HPLC) separation method with photodiode array (PDA) and mass spectrometric (MS) detection. With this method, two distinct elution regions of anthocyanins and flavonols were obtained with near baseline separation of most compounds. Blackberry, blueberry and red wine grape genotypes varied markedly in total anthocyanins and total flavonols as well as oxygen radical absorbance capacity (ORAC). The respective ranges of total anthocyanin (TA) and total flavonol (TF) contents of tested samples were: blackberries, 1143.9–2415.4 and 102.0–160.2 mg kg^?1; blueberries, 1435.2–8227.3 and 172.5–327.5 mg kg^?1; and red wine grapes, 380.9–7904.7 and 21.0–322.2 mg kg^?1. Antioxidant activities and contents of total anthocyanins and total flavonols in blackberries, blueberries and red wine grapes were highly correlated, with linear relationships between ORAC and TA (r_xy = 0.94) and TF (r_xy = 0.90) for grapes, TA (r_xy = 0.95) for blueberries and TA (r_xy = 0.74) for blackberries. Copyright © 2004 Society of Chemical Industry     

Color,Phenolics, and Antioxidant Activity of Blackberry (Rubus glaucus Benth.), Blueberry (Vaccinium floribundum Kunth.), and Apple Wines from Ecuador

Seventy wines were produced in Ecuador under different processing conditions with local fruits: Andean blackberries (Rubus glaucus Benth.) and blueberries (Vaccinium floribundum Kunth.) and Golden Reinette apples. Wines were evaluated for antioxidant activity (AA) using the radical scavenging capacity (DPPH) method, total phenolic content (TPC) using the Folin–Ciocalteu method, total monomeric anthocyanins (TMAs) using the pH differential test, and color parameters using VIS‐spectrophotometry. For blackberry wines, ellagitannins and anthocyanins were also analyzed using high‐performance liquid chromatography with diode‐array detection (HPLC‐DAD). Apples wines (n = 40) had the lowest TPC (608 ± 86 mg/L) and AA (2.1 ± 0.3 mM Trolox). Blueberry wines (n = 12) had high TPC (1086 ± 194 mg/L) and moderate AA (5.4 ± 0.8 mM) but very low TMA (8 ± 3 mg/L), with a color evolved toward yellow and blue shades. Blackberry wines (n = 10) had the highest TPC (1265 ± 91 mg/L) and AA (12 ± 1 mM). Ellagitannins were the major phenolics (1172 ± 115 mg/L) and correlated well with AA (r = 0.88). Within anthocyanins (TMA 73 ± 16 mg/L), cyanidin‐3‐rutinoside (62%) and cyanidin‐3‐glucoside (15%) were predominant. Wines obtained by cofermentation of apples and blackberries (n = 8) showed intermediate characteristics (TPC 999 ± 83 mg/L, AA 6.2 ± 0.7 mM, TMA 35 ± 22 mg/L) between the blackberry and blueberry wines. The results suggest that the Andean berries, particularly R. glaucus, are suitable raw materials to produce wines with an in vitro antioxidant capacity that is comparable to red grape wines.     

Pulsed electric field treatment prior to freezing carrot discs significantly maintains their initial quality parameters after thawing

The interaction of pulsed electric fields (PEF) with different cryoprotectant and texturizing agents in quality retention of carrot discs was analysed. Increasing the permeability properties by PEF may lead to better accessibility of intracellular materials to freezing and thus reducing the freezing time, leading to better maintaining the texture after thawing. Carrot discs of 5 mm thickness were immersed in different solutions of CaCl₂, glycerol, trehalose and tap water, and subsequently were treated with PEF (1 kV/cm, 100 pulses, 4 Hz). Then, the samples were drained and packed along with a control group in separate prepared polypropylene pouches. All the samples were frozen at ?18 °C for 24 h and thawed during 3 h at ambient temperature (20 °C) the following day. The quality of the thawed carrot discs was certified by measuring weight loss, firmness, microscopic studies and CIE colorimetric attributes. All the PEF‐treated samples, no matter what solution they were soaked in, could significantly (P < 0.05) maintain the firmness as well as colour attributes. However, it was deducted that application of CaCl₂ in conjunction with PEF can result in a firmer texture. Firmness analyses determined that application of PEF alone results in 5.84 N, while its combination with CaCl₂ leads to higher value of 6.63 N. Firmness in control samples was found to be 3.46 N. The SEM studies supported the results of firmness analysis and depicted more integrity in the cell walls of the samples treated with CaCl₂ and glycerol. The weight loss values varied among different samples, and the highest amount and lowest amount were reported in CaCl₂ and solely PEF‐treated samples, respectively. There was no significant difference between the colour attributes measured in different groups including control sample (P > 0.05).     

Phenolic Content and Antioxidant Activity of Raspberry and Blackberry Cultivars

ABSTRACT: Raspberry (Aksu Kırmızısı, Rubin, Newburgh, Hollanda Boduru, Heritage) and blackberry (Bursa 1, Bursa 2, Jumbo, Chester) cultivars were assayed for antioxidant activity (determined as 2,2-azino-di-[3-ethylbenzothialozine-sulphonic acid][ABTS], 2,2-diphenyl-1-picrylhydrazyl radical [DPPH], and cupric ion reducing antioxidant capacity [CUPRAC]), total phenol, total flavonoid, and total anthocyanin contents. In addition, 10 anthocyanins and anthocyanidins were determined in raspberry and blackberry by liquid chromatography-mass spectrometry (LC-MS/MS). Raspberry and blackberry had the highest ABTS, DPPH, CUPRAC, total phenol, and total flavonoid contents in methanol extracts, whereas total anthocyanin contents were the highest in water extracts. The antioxidant activity of the raspberry and blackberry was directly related to the total amount of phenolic compounds detected in the raspberry and blackberry. All antioxidant activity values were highly correlated with anthocyanin content in blackberry (0.93 ≤ r ≤ 0.99, P = 0.05). On the other hand, high correlation between total flavonoid content and antioxidant activity was recorded in water extract of blackberry (0.91 ≤ r ≤ 0.93, P = 0.05). ABTS value was highly correlated with total flavonoid content in methanol extract (r = 0.90), whereas total flavonoid content was relatively less correlated with DPPH (r = 0.85) and CUPRAC (r = 0.89).     

Detection of frozen-thawed salmon (Salmo salar) by a rapid low-cost method

The aim of this study was to evaluate a rapid low-cost system based on impedance spectroscopy as an alternative method to differentiate between fresh and frozen-thawed salmon. Samples of fresh salmon and others submitted to freezing at −18 °C or to 2 freezing cycles, kept in frozen storage for different times, were analysed. In general, no significant differences in moisture, total volatile basic nitrogen, pH, texture parameters, K₁ value, or microbial counts between the different samples were observed. This revealed that the freezing process, storage time or number of freezing cycles did not affect the physico-chemical parameters of fish samples, except for water holding capacity, which was significantly lower in all frozen samples compared with fresh salmon. The results showed that impedance spectroscopy was unable to differentiate between different storage times under frozen conditions; however, this technique could be a useful tool to detect fish submitted to freezing process.     

Flavonol glycosides and antioxidant capacity of various blackberry and blueberry genotypes determined by high‐performance liquid chromatography/mass spectrometry

Flavonol glycoside composition and content in blueberry and blackberry extracts were determined using a high‐performance liquid chromatographic (HPLC) separation method coupled with photodiode array (PDA) and mass spectrometric (MS) detection. The hydrophilic antioxidant capacities of crude and fractionated flavonol extracts were also determined by the oxygen radical‐absorbing capacity (ORAC_FL) and photochemiluminescence (PCL) assays. Eight flavonols of quercetin and quercetin–sugar conjugates were identified in Kiowa blackberry, namely rutinoside, galactoside, methoxyhexoside, glucoside, pentoside, [6″‐(3‐hydroxy‐3‐methylglutaroyl)]‐β‐galactoside, glucosylpentoside and oxalylpentoside. Thirteen flavonols were detected in Ozarkblue blueberry. Of these, myricetin 3‐hexoside and 12 quercetin–sugar conjugates, namely rutinoside, galactoside, methoxyhexoside, glucoside, pentoside, glucosylpentoside, caffeoylglucoside, oxalylpentoside, rhamnoside, dimethoxyrhamnoside, acetylgalactoside and acetylglucoside, were identified. In Bluecrop blueberry, two additional quercetin–sugar conjugates were identified, namely glucuronide and caffeoylgalactoside. Quercetin glycosides accounted for 75% of total flavonols in the blueberry genotypes. Total flavonol contents ranged from 99 to 150 mg kg^?1 for blackberries and from 192 to 320 mg kg^?1 for blueberries. Quenching of peroxyl and superoxide anion radicals by the flavonol fractions ranged from 1.5 to 2.3 mmol Trolox equivalents (TE) kg^?1 and from 0.5 to 0.7 mmol TE kg^?1 respectively for blackberries and from 2.9 to 5.2 mmol TE kg^?1 and from 0.8 to 1.4 mmol TE kg^?1 respectively for blueberries. The HPLC method allowed for complete separation and identification of flavonols commonly found in blackberries, and blueberries. Our results showed that blueberry and blackberry genotypes varied significantly in flavonol content and antioxidant capacity. Even though total flavonol content did not correlate well with antioxidant capacity, their ability to scavenge peroxyl and superoxide anion radicals was apparent. Copyright © 2005 Society of Chemical Industry     

Texture improvement of fermented minced pepper under vacuum impregnation with pectin methylesterase and CaCl2 during fermentation

Fermented minced pepper (FMP) usually suffers from the deterioration of texture quality during fermentation, which can affect sensory and consumer acceptance. In this study, vacuum impregnation (VI) with CaCl₂, pectin methylesterase (PME) and CaCl₂ and PME (PME + CaCl₂ + VI) were compared to improve the texture quality of FMP. FMP treated with PME + CaCl₂ + VI showed the relatively intact cells structure after fermentation. In that case, its firmness maintained high level, while water-soluble pectin (WSP) content was minimum after fermentation. Meanwhile, the molar ratio of most monosaccharides of WSP in PME + CaCl₂ + VI treated FMP decreased, while rhamnose (Rha) molar ratio significantly (p < 0.05) increased after fermentation. The high Rha content represents the stability of rhamnogalacturonan-I linear skeleton of WSP. The negative effect on molecular weight of WSP was delayed by PME + CaCl₂ + VI treatment, and its peak area and value increased after fermentation. Atomic force microscope images indicated that PME + CaCl₂ + VI treatment could retain the long chain and branch structures, and inhibit the degradation of WSP net-like structure at some extent. Hence, PME + CaCl₂ + VI treatment was effective to improve the texture of FMP and inhibit the solubilisation of WSP via the formation of cross-linked pectin chains between Ca²⁺ and demethylesterified pectin.     

Consumer Acceptability of Cucumber Pickles Produced by Fermentation in Calcium Chloride Brine for Reduced Environmental Impact

Fermentation of cucumbers in calcium chloride (CaCl₂) brine has been proposed as an alternative process to reduce the environmental impact of traditional, high salt fermentations. The objective of this research was to determine whether consumer acceptability of pickle products would be impacted by fermentation and storage of cucumbers in CaCl₂ brine. Cucumbers were fermented and stored with 0.1M CaCl₂ or 1M sodium chloride (NaCl) in open‐air, 3000 gal tanks at a commercial facility and processed into hamburger dill chips containing 0.38M NaCl. Cucumbers fermented in CaCl₂ required additional desalting to reduce CaCl₂ concentrations to that of current products. Consumers (n = 101) showed no significant preference for pickles from different fermentation treatments, whether stored for 2 mo (P = 0.75) or 8 mo (P = 0.68) prior to processing. In contrast, NaCl fermented pickles were preferred over CaCl₂ fermented pickles stored for 10 mo and desalted only once (P < 0.01). A series of preference tests indicated that the taste of CaCl₂ was not the factor affecting consumer preference, and the 50% detection threshold of CaCl₂ in dill pickle chips was found to be 61.8 ± 7.6 mM, indicating that processors could potentially use CaCl₂ fermentations with a single desalting step. Consumer liking of flavor (n = 73) was not influenced by fermentation in CaCl₂ or by 23 or 35 mM CaCl₂ in finished products (P > 0.05), but variability in texture decreased consumer liking (P < 0.05). Although promising, individual fermentation variability and texture quality of CaCl₂ fermented products should be further evaluated prior to broad implementation of this process.     

Enzyme induced loss of sucrose in berry fruit juices

Varied concentrations of sucrose have previously been reported in freshly picked berry fruits. We have observed that sucrose in juice extracts from berries decreased markedly with time. The loss of sucrose added to raspberry and loganberry juice is attributed to the action of the enzyme, invertase. Heat inactivation immediately after picking reduced the loss of sucrose in raspberries and blackberries. Knowledge of these changes might influence the methods of harvesting, storage and processing.