Browning Index Research Articles

Control of Browning, Enzyme Activity, and Quality in Stored Fresh-cut Fruit Salads through Chitosan Coating Enriched with Bergamot Juice Powder.

In this study, fresh-cut fruit salads composed of apples, pears, kiwis, and pineapples were stored at +4 °C for 18 days under distinct conditions: non-coated (NC), chitosan-coated (CH), and bergamot juice powder extract-enriched chitosan-coated (CHBE). Storage endpoint decay percentages were as follows: NC group: 100%, CH group: 26.67-53.3%, CHBE group: 13.33-26.67%. CHBE had the highest moisture content (87.05-89.64%), soluble solids (12.40-13.26%), and chroma values (2.35-6.60). CHBE and NC groups had 2.10% and 6.61% weight loss, respectively. The NC group had the highest polyphenol oxidase activity (19.48 U mL-1) and browning index (0.70 A420/g); CH group: 0.85 U mL-1, 0.35 A420/g; CHBE group: 0.57 U mL-1, 0.27 A420/g. CHBE showed a titratable acidity of 1.33% and pH 3.73 post-storage, impeding microbial proliferation with the lowest counts (2.30-3.24 log CFU g-1). The microbial suitability of the NC group diminished after day 6, with an overall preference score of 1.00. Conversely, the CH and CHBE groups scored 3.15 and 4.56, highlighting the coatings' effectiveness. Bergamot juice powder extract further enhanced this, mitigating browning and enhancing quality. Results reveal tailored coatings' potential to extend shelf life, improve quality, and enhance fruit salads' acceptability. This study underscores the importance of edible coatings in addressing preservation challenges, emphasizing their role in enhancing food quality and consumer acceptability. Incorporating edible coatings is pivotal in mitigating deterioration issues and ensuring the overall success of fresh-cut fruit products in the market.

Effect of Ascorbic Acid and Polythylene Plastic Packaging on Browning and Shelf Life of Langsat Fruit (Lansium domesticum)

Langsat (Lansium domesticum) is a tropical fruit classified as a climacteric fruit that can only last 4-6 days after harvesting. Skin colour is easier to brown and black after 4 days of harvesting. This condition does not affect the fruit flesh, but visually, it becomes unappealing. Ascorbic acid and polyethylene plastic packaging could be applied to extend shelf life and slow browning. This study aims to investigate the effect of different concentrations of ascorbic acid treatment and polyethylene plastic (PE) packaging on the browning index and shelf life of lan and to determine the best concentration of ascorbic acid during storage at 15 °C. The treatments used in this study involved immersing langsat fruit in different ascorbic acid concentrations: 1.5%, 2%, and 2.5%, respectively. The langsat fruit was then packaged using polyethylene plastic and stored at 15 °C. The results showed that using ascorbic acid could delay browning by up to 14 days, with the lowest browning index found in langsat fruit immersed in 2.5% ascorbic acid concentration and packaged in polyethylene plastic. Polyethylene plastic packaging and ascorbic acid during storage affected the shelf life of langsat fruit, extending it to 14 days.

Optimization of active pectin coating formulation and its effect on surface morphology and shelf-life of white button mushroom (Agaricus bisporus)

The present work aimed to optimize an active pectin-based coating to preserve microbial and enzymatic stability and maintain the quality parameters of white button mushrooms (WBM), thus increasing their shelf stability. d-optimal mixture design was implemented to study the effect of pectin (X1), ascorbic acid (X2), and ethylene-diamine-tetra acetic acid (EDTA) (X3) on polyphenol oxidase (PPO) inhibition, browning index, and total phenolic content. The optimal coating was a mixture of 2.55% w/v pectin, 0.67% w/v ascorbic acid, and 0.78% w/v EDTA. Further, the optimally coated WBM was stored for 6 days at 20 ± 1 °C. The coating on WBM significantly prevented the growth of natural microflora in the sample. Similarly, a maximum of 84% PPO inhibition was achieved at the end of the storage period. A minimum browning index (BI) of 66 was observed after six days of storage, significantly lower than that of the uncoated sample with a BI of 72.72 ± 0.90. Maximum phenolic content of 10.23 mgGAE/g WBM (dry basis) was preserved till day 6, while the antioxidant capacity was 7.16 ± 0.20 mg GAEAOC/g WBM (dry basis). Based on microbial safety and overall quality parameters, the optimal pectin-based ascorbic acid and EDTA-enriched coating led to a shelf-life of 4 days against 2 days for uncoated mushrooms at 20 °C. The optimized coating of mushrooms resulted in competitive inhibition of PPO. Fourier transform infrared (FTIR) spectroscopy revealed that EDTA and optimized coating modulated the secondary structure conformation in the amide I region. Microstructural analysis of the mushroom cap surface through scanning electron microscopy (SEM) showed that the optimized coating formed a homogeneous protective barrier on the mushroom surface, leading to the closure of intercellular spaces on the surface. The optimized coating can help mitigate postharvest losses due to the high perishability of white button mushrooms and provides a valuable solution for the industry to enhance product quality and safety.

Bebida deportiva isotónica a base de jugo de piña: Estabilidad durante su almacenamiento acelerado

It was evaluated the behavior, during accelerated storage, of the quality indicators of an isotonic sport drink made from the mixture of pineapple juice, distilled water, sucrose and NaCl. The drink was packed in amber glass bottles was pasteurized at 80 °C for 5 min in a water bath. The drink was stored at 45, 50 and 55 °C with the aim of achieving accelerated deterioration. The drink presented a total sugar content of 7.6%, osmolality of 328 mOsm/kg and sensory acceptance corresponding to the category -I like it slightly-. At the end of storage at each temperature, there was a decrease in brightness and an increase in the values of a* and b*, related to the increase (p ≤ 0.05) of the browning index (IP) and the moment of sensory rejection, due to a notable loss of pineapple color. The behaviors of the IP at each temperature were adjusted to polynomial models of order five with high coefficients of determination (> 0.98). This study provides useful information for the optimization of beverage production, quality control and spoilage prediction, which could contribute to the development of new products and satisfy consumer needs.

Perbandingan Tepung Talas Kimpul (Xanthosoma sagittifolium) Termodifikasi dan Tepung Kacang Merah (Phaseolus vulgaris) Terhadap Karakteristik Non-Flaky Crackers


 
 
 Non-flaky crackers are crackers that are not layered inside. Generally, crackers which are made from wheat flour have a low fiber content, cocoyam autoclaving-cooling modified flour can be used as a substitute for wheat flour to increase dietary fiber. Cocoyam modified flour has a low protein content, so red bean flour needs to be added to increase protein content of crackers. The purpose of this study is to determine the effect of the ratio of modified cocoyam flour and red bean flour on non-flaky crackers and to obtain non- flaky crackers with the best characteristic. The research design of this study is completely randomized design with 5 treatment levels, 90:10, 80:20, 70:30, 60:40, and 50:50 repeated 3 times to obtain 15 experimental units. The data obtained was analyzed by ANOVA, then proceed with DMRT test. The results showed that the comparison of modified cocoyam flour and red bean flour had a significant influence (P<0,05) on chemical properties including water content, texture tests including hardness, fracture, crunchiness, chewiness, cohesiveness, color test including L*, a*, b*, browning index, hedonic test including color, texture, taste, overall acceptance. The best treatment was the comparison of 70% modified cocoyam flour and 30% red bean flour with hardness 75,70 N, fracture 4,87 N, crunchiness 37,50 Nmm, chewiness 27,88 N, cohesiveness 0,45, water content 2,71%, ash content 3,89%, protein content 9,74%, fat content 0,17%, carbohydrate content 83,49%, dietary fiber content 4,88%, resistant starch content 3,95%, browning index 68,55 (L* 48,00; a* 7,30; b* 34,83), the color is like slightly, the aroma is neutral, the texture is like slightly, the taste is like slightly, and the overall acceptance is like slightly.
 
 

Arginine: a useful treatment to delay enzymatic browning of fresh-cut pear and apple

This study examined the effect of arginine treatments on the prevention of enzymatic browning in fresh-cut apples and pears. For this, 0, 25, 50, 75, and 100 mM, and 0-, 50-, 100-, and 200-mM arginine solutions were prepared for apples and pears, respectively. Slices of both fruits were dipped in these solutions for 5 min and dried for 20 min. Then, they were packaged and stored at 5±1oC temperature and 80-90% relative humidity for 18 days for pears and 12 days for apples. Browning index, color values, weight losses, firmness of slices, and total soluble solids were examined at three-day intervals during storage. The results showed that arginine treatment retarded the enzymatic browning of both apple and pear slices. While arginine suppressed browning at increasing doses, especially at 200 mM in pears, it retarded browning in apple slices at all concentrations. In addition, the fact that the L values were higher than the control and water control applications showed that both apple and pear slices remained lighter in color. Hue values supported both the L and browning index results. Arginine treatment decreased the weight loss; however, it did not affect the firmness of the slices. In addition, arginine treatments did not have a significant effect on the total soluble solid content of apple and pear slices.

Calcium combined with vacuum treatment improves postharvest storage quality of Agaricus bisporus by regulating polyamine metabolism

Calcium (Ca) immersion treatment has been used for the preservation of Agaricus bisporus (A. bisporus), but the effective dosage of Ca absorption has often been disregarded. In our study, vacuum pretreatment was performed to promote Ca infiltration in A. bisporus. Vacuum pretreatment (−0.1 MPa, 5 min, Vac + Ca group) exhibited a super effectiveness in promoting Ca absorption. The results of Ca diffusion simulation using COMSOL Multiphysics showed that Ca level in the center of the sample in the Vac + Ca group increased from 0.1020 to 0.2028 g kg−1 during a period of 0 to 60 min. Additionally, the effects of Vac + Ca treatment on the polyamine (PA) metabolism during a 3-day room temperature storage of A. bisporus were investigated. Vac + Ca treatment resulted in a reduction of putrescine (Put) level and an elevation in spermidine (Spd) level, suggesting that the treatment may facilitate the conversion of Put to Spd. Interestingly, a negative linear correlation between changes in Spd level and both the browning index and weight loss, while a positive correlation was found with alterations in hardness were observed. Moreover, several amino acids and enzymes involved in PA metabolism, including arginine, methionine, ornithine decarboxylase, arginase, S-adenosylmethionine decarboxylase, and spermidine synthase, were also affected by this treatment. Therefore, the increase in Spd induced by Vac + Ca treatment may be one of the underlying mechanisms responsible for extending the postharvest lifespan of A. bisporus.

LcVHA2 and LcVHA3 positively modulate energy metabolism and reduce pericarp browning in litchi fruit after application of Bacillus siamensis

Pericarp browning, postharvest disease, and a short storage life are the leading causes of economic losses in the litchi industry globally. Energy metabolism plays an integral role in regulating browning, disease resistance, and the shelf-life of litchi fruit. The ability of Bacillus siamensis (N-1) to control postharvest diseases and maintain the quality of a variety of tropical fruits has previously been reported, however its effect on litchi fruit has not been explored. In the present study, we investigated the effect of Bacillus siamensis (N-1) on the postharvest energy metabolism of litchi fruit and its relation to pericarp browning, as well as the expression of energy-related genes. Results indicated that litchi fruit treated with Bacillus siamensis (N-1) exhibited a significant improvement in storability as evidenced by a decrease in the rate of the browning index (BI), color change, rate of weight loss, and laccase (LAC) and polyphenol oxidase (PPO) activity. There was also an increase in the energy status of litchi fruit due to the enhanced activity of Ca2+-ATPase, H+-ATPase, oxidase (CCO), cytochrome C, and succinic dehydrogenase (SDH), as well as the expression of their corresponding genes. LcVHA2 and LcVHA3, two major vacuolar-type H+-ATPase genes, were cloned and characterized. Phylogenetic analysis revealed that these genes are members of the V-ATPase subunit D and E gene family, respectively. Both heterologous (in tomato) and homologous (in litchi) transient overexpression (OE) assays indicated that both LcVHA2 and LcVHA3 have the potential to delay changes in fruit coloration and pericarp browning, but also increase ADP, ATP, and V-H+-ATPase activity, as well as the energy charge (EC) of fruit. Collectively, results indicated that the LcVHA2 and LcVHA3 play a critical role in preventing the browning and senescence of litchi fruit. This study provides new information on the ability of Bacillus siamensis (N-1), which has been previously demonstrated to be an effective postharvest biocontrol agent, to also improve the storage life of litchi fruit.

Quality assessment of promising garlic (Allium sativum L.) varieties based on principal component analysis

Physicochemical properties, pungency, anti-nutritional factors, cutting strength, and colour attributes of seven promising garlic varieties were assessed for their potential application. The garlic varieties were found to be slightly acidic (pH 6.08 - 6.77), and contained varying amounts of crude protein, carbohydrate, crude fat, ash, crude fibre, acidity, and total soluble solids (TSS). The pungency factor as pyruvic acid was found to be in the range of 34.84 - 86.69 μmol/mL, whereas anti-nutritional factors such as saponin (6.63 - 13.98 g), phytic acid (0.03 - 0.6 g), and tannin (0.18 - 0.39 gCE) per 100 g on a fresh weight basis were present. The Bhima purple (BP) variety with a purple tinge showed higher saponin content than the other varieties with a whitish tinge. The cutting strength of garlic cloves varied between 17.20 and 104.61 N. Physical and gravimetric properties were estimated and found to be variety-dependent (p ≤ 0.05). Colour attributes like L* (lightness), a* (redness), b* (yellowness), chroma, hue, and browning index were significantly different (p ≤ 0.05) for all the garlic varieties. The minimum hue value, and maximum a* and b* values, browning index (BI), and chroma were found in the BP variety. Principal component analysis as a significant multivariate analysis tool was applied to assess the existence of correlation among the estimated parameters. It was found to be 75.41% of the total variance when considering the first three principals. Haryana garlic-17 (HG-17) variety showed significant quality as it yielded positive correlation with the maximum number of quality attributes.

Analysis of the browning reaction in a sorbitol/glycine model: Formation and degradation of precursors, glucose and α-dicarbonyl compounds during heating

Browning can occur in the matrices of alditol and amino acids due to heating or long-term storage, which poses challenges in achieving the desired appearance stability. To investigate the mechanism of browning in the sorbitol-glycine system, we evaluated the evolution of typical intermediates, including glucose and α-dicarbonyl compounds (α-DCs), during heating at 100 ˚C. The browning index and intermediate products of the sorbitol-glycine system increased more rapidly compared to those of the sorbitol system. After heating for 10 h, the browning index of the sorbitol-glycine system was eight times higher than that of sorbitol alone. In the presence of glycine, sorbitol underwent continuous conversion into glucose. After 10 h of heating, the concentration of glucose in the sorbitol-glycine system reanched 726.6 mg/L, which was approximately 63 times higher than that in the sorbitol system. Mass spectrometry analysis revealed the presence of α-DCs such as 3-deoxyglucosone (3-DG), glyoxal (GO), methylglyoxal (MGO), 2,3-butanedione (2,3-BD), in the sorbitol-glycine system. These compounds were precursors of melanoidins, indicating the occurrence of the Maillard reaction and resulting in the browning of the system. Therefore, the browning process in the sorbitol-glycine system involved two stages of reactions: the conversion of sorbitol to glucose and the Maillard reaction between glucose and glycine.

Is it possible to produce canned champignon mushrooms with less sulfite?

This study aimed to evaluate the feasibility of reducing sulfite levels in canned mushrooms (Agaricus bisporus). Four formulations were developed: without sulfite and without condiment (F1); without sulfite but with condiment (F2); with sulfite but without condiment (F3); and with both sulfite and condiment (F4). The control group (C) consisted of traditional canned mushrooms prepared by the producer. These treatments were evaluated over a 42-day period. Acidity and pH analyses revealed that the control and F1 maintained a stable pH (<4.5) for 42 days. The formulations exhibited a greater browning index than fresh mushrooms at time zero. F3 demonstrated the smallest overall color difference (ΔE) between storage times 0 and day 42. A consumer study indicated that the addition of sulfite positively influenced the color of canned mushrooms in relation to purchase intention. However, when the influence of labeling was evaluated, sample F1, labeled as “absence of sulfite,” elicited greater purchase intention among consumers. Although consumers traditionally prefer pale yellow mushrooms, often obtained through sulfites, this study suggests the commercial viability of canned champignons with controlled sulfite content when coupled with appropriate marketing strategies.

Bamboo leaf extract treatment alleviates the surface browning of fresh-cut apple by regulating membrane lipid metabolism and antioxidant properties.

The effect of bamboo leaf extract (BLE) on controlling the browning of fresh-cut apple stored at 4 °C was investigated. Browning index, H2 O2 content, O2 - production rate, malondialdehyde (MDA) contents, total phenolic content (TPC) and soluble quinone content (SQC), the activities of polyphenol oxidase (PPO), peroxidase (POD), lipoxygenase (LOX), superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), DPPH (2,2-diphenyl-2-picryl-hydrazyl) and ABTS [2,2-azinobis(3-ethylbenzothiazoline- 6-sulfonic acid)] radical scavenging activities, and the expression of genes related to browning were all investigated. BLE effectively alleviated the surface browning of fresh-cut apple, accompanied by a reduction in SQC, LOX activity, H2 O2 , O2 - production rate and MDA accumulation. Furthermore, BLE treatment enhanced the TPC, enzymatic (SOD, CAT, APX and POD) and non-enzymatic antioxidant activities. Principal component analysis and Pearson correlation analysis found the browning inhibition by BLE is not through the reduction of phenolic substrates and PPO activity. BLE controls the browning of fresh-cut apple by increasing the antioxidant capacity to scavenge ROS, which could alleviate oxidative damage and maintain the membrane integrity. © 2023 Society of Chemical Industry.

스팀 및 동결 전처리가 건조 감잎 열수추출물의 이화학적 특성에 미치는 영향

This study was conducted to develop a preservation technology that can induce changes in physicochemical properties to effectively utilize of persimmon leaves. The application effects of steaming or freezing technique were investigated. Astringent persimmon leaves were steam-blanched (100°C, 30 sec) or frozen (−20°C, 15 d), followed by hot-air drying (50°C). The physicochemical properties of the extract obtained by hot-water leaching from the dried leaves were compared. The extract of leaves dried without pretreatment was used as a control. L* value was higher in steamed than in control and frozen. a* value was highest in the control. The browning index was higher in the frozen and lower in the steamed than in the control. Soluble solids were the highest in the steamed and the lowest in the frozen. Sucrose content was relatively high in the steamed, and the glucose and fructose contents were relatively high in the frozen. Total polyphenol content and DPPH radical scavenging activity were higher in steamed and lower in frozen than in control. Thus, it was confirmed that steam or freeze pretreatment after harvesting persimmon leaves affects the extraction yield, color, antioxidant capacity and component changes of dried persimmon leaves. Unlike steaming, freezing pretreatment showed the effect of promoting decomposition and browning reactions, and it is considered useful when such an effect is needed.

Quality characteristics, antioxidant activity, and acrylamide content of lotus root chips prepared using different processing methods.

Lotus root chips were prepared using five different methods (freeze-drying, microwaving, air-frying, oil-frying, and oven-baking), and their quality characteristics, bioactive substance content, and antioxidant activity were determined. The amount of acrylamide generated during manufacturing was determined. The proximate content of the chips varied depending on the manufacturing method. Based on color determination, lightness was highest in freeze-dried chips and lowest in oven-baked chips. Oil-fried chips had the highest redness, yellowness, and browning index. The total polyphenol, flavonoid content, and antioxidant activities were the highest in freeze-dried chips and the lowest in oven-baked chips. Air-fried chips had the highest (746.92µg/g) acrylamide content, while freeze-dried chips had the lowest (1.82µg/g). Compared to other methods, freeze-drying retained the maximum bioactive compound content and antioxidant activity, leading to the lowest acrylamide formation. These findings highlight a suitable method and provide basic data for future lotus root chip manufacturing.

Effect of Nitric Oxide on Browning of Stem Tip Explants of Malus sieversii

Browning is a major problem in the tissue culture of woody plants. Previous studies have shown that nitric oxide (NO) plays a role in regulating plant responses to stress, but its effect on browning in the tissue culture of Malus remains unclear. This study aimed to investigate the impact of exogenous NO donor sodium nitroprusside (SNP) on the browning of Malus sieversii stem tip explants. The results demonstrated that the addition of 50 μM SNP significantly reduced explant browning. Further analysis revealed that exogenous NO decreased the browning index (BD) and levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion radical O2−. Additionally, NO treatment increased the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). NO treatment also enhanced the activity of phenylalanine ammonia lyase (PAL), which contributed to the accumulation of flavonoids and inhibited the activity of polyphenol oxidase (PPO) and peroxidase (POD), which are key enzymes involved in the browning process. Furthermore, 50 μM SNP significantly promoted the accumulation of non-enzymatic antioxidants such as proline (Pro), soluble sugar (SS), and soluble protein (SP). Therefore, the results suggest that NO is able to counteract excessive reactive oxygen species (ROS) damage by enhancing both the enzymatic and non-enzymatic antioxidant systems, resulting in a reduction in browning in stem tip explants. Consequently, an improvement in the in vitro propagation efficiency of Malus sieversii shoot tip explants can be achieved.

Impacts of storage practices on the physical, culinary and sensory quality of Kponan yam (Dioscorea cayenensis-rotundata) from Côte d'Ivoire during storage.

Kponan is the most popular yam (Dioscorea cayenensis-rotundata) variety in Côte d'Ivoire. Unfortunately, losses due to rotting during storage do not ensure a regular supply to markets. This study aimed to identify the impacts of cultivation and storage practices in the main production areas on physical, cooking and sensory characteristics of Kponan. To this end, yams grown in Bondoukou were stored in straw huts, those grown in Bouna in pits and those grown in Kouassi-Kouassikro in the open air, according to the practices of each producer. Findings showed that yams grown in Kouassi-Kouassikro and stored in the open air recorded the highest rot rate (58.09%) compared to the rot rate of yams grown and stored in pits in Bouna (26.67%) and those grown and stored in straw huts in Bondoukou (53.34%). However, the weight losses were respectively 10.47% (Bouna), 28.57% (Kouassi-Kouassikro) and 36.19% (Bondoukou). Loss rates varied significantly from 43.80% (pits) to 100% (huts and open air). Furthermore, the browning indices were higher for yams grown in Kouassi-Kouassikro and freshly harvested (26.09) compared to the browning index recorded for yams grown and freshly harvested in Bouna (23.43) and in Bondoukou (24.73). Concerning the hardness of yams, it decreased during storage for yams grown and stored in pits in Bouna (38.94 to 25.20 N) and for those grown and stored in straw huts in Bondoukou (39. 39 to 26.42 N). The shelf life and culinary and sensory characteristics of Kponan depend on the cultivation and storage practices of each producer. © 2023 Society of Chemical Industry.

Role of Drying Technologies on the Drying Kinetics, Physical Quality, Aroma, and Enzymatic Activity of Pineapple Slices

With a loss of about 50% of fruits and vegetables annually, there is a continuous need to improve food handling from the farm to the consumer. The solution may come partially from the selection of proper processing techniques that produce healthy and high-quality sustainable food, preserve natural resources, and contribute to prospering local economies. Pineapple is one of the most consumed fruits worldwide due to its remarkable sensorial and health-promoting attributes. Nevertheless, pineapple’s high moisture content (81–86%) impedes its long-term preservation, resulting in product losses and economic, social, and environmental challenges. Drying is the oldest processing technique for most fruits and vegetables. However, the investigation of modern technologies, such as infrared drying of pineapple, is limited. Moreover, industries are investigating different methods to dry faster, thereby saving energy and reducing environmental impact. Hence, this study used four drying methods to dry pineapple slices to allow the estimation of the most promising technique: infrared drying (ID), freeze-drying (FD), convective drying (CD), and relative humidity convective drying (RHCD). The impact of these dehydration techniques on drying kinetics, physical attributes (color, texture, rehydration, microstructure), aroma, and enzymatic activity (polyphenol oxidase, peroxidase) were reported. The results showed that ID had the highest coefficient of effective moisture diffusivity and drying rates and the shortest drying period (33.45%, 36.18%, and 76.12% lower than CD, RHCD, and FD, respectively). Drying curves were successfully fitted with the parabolic and logarithmic models, which showed higher coefficients of determination and lower reduced chi-square and root mean square error than the Newton and inverse logarithmic models. FD and ID triggered minor browning indexes, leading to the brightest products. RHCD and ID slices had the highest textural values and aroma concentrations, while FD samples showed the lowest. However, FD samples had a higher rehydration ratio than other dried products and showed slight structural modifications. Regarding polyphenol oxidase and peroxidase inactivation, ID was superior, followed by CD, RHCD, and FD. The actual results suggest that infrared drying could be an efficient technique for the obtention of high-quality dehydrated pineapple fruits in a short time.

Sucrose and brassinolide alleviated nitrite accumulation, oxidative stress and the reduction of phytochemicals in kale sprouts stored at low temperature

Browning, nitrite accumulation, oxidative stress, and loss of nutrients in postharvest sprout during low-temperature storage are important issues that affect storage quality of sprouts. This study evaluated the effects of sucrose, brassinolide (BR), and their combination on the growth and development of fresh kale sprouts, and reactive oxygen metabolism, ascorbate-glutathione (AsA-GSH) cycle, browning, nitrite content, and bioactive ingredients of kale sprouts stored at low temperature, in order to improve the physiological traits of postharvest sprouts, resist the oxidative stress in sprouts during low-temperature storage and inhibit the loss of plant nutrients. Compared with sucrose or BR alone, the combined treatment increased fresh weight, hypocotyl length, AsA/DHA ratio, glutathione reductase activity, riboflavin, cellulose, and free amino acid contents, and decreased weight loss rate, browning index (BI), malondialdehyde (MDA) and dehydroascorbic acid content, ascorbate peroxidase and dehydroascorbate reductase activities in sprouts stored at low temperature. The riboflavin, cellulose, and free amino acid contents in the combined-treated group were higher 57.5%, 119.9%, and 66.7% than those in the control group of fresh samples (CK0), respectively, and there were no significant differences in BI and MDA content between CK0 and the combined-treated groups. These results indicated that the combination of sucrose and BR could better alleviate the reduced quality of kale sprouts stored at low temperature by regulating the weight loss rate and AsA-GSH cycle, so as to maintain the nutrients and antioxidant capacity of kale sprouts to the maximum extent.

Water thermodynamics and lipid oxidation in stored whey butter

Whey butter is the result of the rational use of the whey component, which is cream whey. It is an alternative to milk cream butter. The aim of the presented study was to analyze the effect of storage conditions on water thermodynamics and cholesterol oxidation products as reliable markers of quality and safety. After 4 mo of storage, the water loss (at 3°C and 13°C) and water activity in whey butter (only at 13°C) were reduced. Three-factorial ANOVA showed that the value of water activity was independent of the type of butter in interaction with the storage temperature. The duration of the translational movement of water molecules from the inside of whey butter was definitely longer than in butter and shortened with storage time. This was in contrast to butter. For whey butter stored at 13°C, the kinetics of the movement of water molecules was at the highest speed. In the case of whey butter and butter, the higher storage temperature almost doubled the gloss. Increasing the temperature to 13°C resulted in different yellowness index, chroma, and browning index between whey butter and butter. There were no statistically significant differences in the percentage of fatty acids and triacylglycerols in whey butter and milk cream butter during storage. In whey butter, compared with butter, the cholesterol content was higher, but the amount of cholesterol oxidation products was smaller. However, in whey butter, these amounts increased significantly. The presence of epoxides and their transformation products (i.e., triol cholesterol) was found in storage whey butter.

Microwave-accelerated pretreatment technique in green extraction of oil and bioactive compounds from camelina seeds: Effectiveness and characterization

Abstract The effect of microwave pretreatment and moisture levels of Camelina sativa seeds on the quality of extracted oil by cold press was investigated. The seed moistures were adjusted to 2.5%, 5.0%, 7.5%, and 10.0% and pretreated with microwaves for 0, 1, 2, and 3 min. Microwave pretreatment (3 min) of the seeds with 2.5% moisture increased the oil extraction yield by ∼11% compared to the control sample. The highest amount of acidity (0.564 g FFA·g−1 oil), peroxide value (2.4 meq O2·kg−1 oil), carotenoid (5.26 mg·kg−1 oil), and browning index (0.710) were found in the oil extracted from seeds with 10% moisture and 3 min microwave pretreatment. The total phenolic compound was increased by microwave pretreatment but was mitigated by the seed moisture content, and the highest amount (208.24 mg caffeic acid·100 g−1 oil) was observed at 3 min microwave pretreatment of the seeds with 2.5% moisture. Chlorophyll content decreased by both microwave pretreatment and seed moisture content in camelina oil. Generally, the fatty acid composition of the extracted oils was not affected by the seed pretreatments. In conclusion, pretreatment of the camelina seeds before oil extraction is suggested to obtain a high oil extraction yield with a good quality oil.