Sucrose Loss Research Articles

Degradation of hydroxycinnamic acid mixtures in aqueous sucrose solutions by the Fenton process.

The degradation efficiencies and behaviors of caffeic acid (CaA), p-coumaric acid (pCoA), and ferulic acid (FeA) in aqueous sucrose solutions containing the mixture of these hydroxycinnamic acids (HCAs) were studied by the Fenton oxidation process. Central composite design and multiresponse surface methodology were used to evaluate and optimize the interactive effects of process parameters. Four quadratic polynomial models were developed for the degradation of each individual acid in the mixture and the total HCAs degraded. Sucrose was the most influential parameter that significantly affected the total amount of HCA degraded. Under the conditions studied there was a <0.01% loss of sucrose in all reactions. The optimal values of the process parameters for a 200 mg/L HCA mixture in water (pH 4.73, 25.15 °C) and sucrose solution (13 mass %, pH 5.39, 35.98 °C) were 77% and 57%, respectively. Regression analysis showed goodness of fit between the experimental results and the predicted values. The degradation behavior of CaA differed from those of pCoA and FeA, where further CaA degradation is observed at increasing sucrose and decreasing solution pH. The differences (established using UV/vis and ATR-FTIR spectroscopy) were because, unlike the other acids, CaA formed a complex with Fe(III) or with Fe(III) hydrogen-bonded to sucrose and coprecipitated with lepidocrocite, an iron oxyhydroxide.

Inhibitory Effect of Pre-harvest Foliar Application of Zinc Sulphate on Sucrose Inversion in the Harvested Sugarcane

Sugar recovery in sub-tropical India is low during late milling season despite improved cane varieties and management practices. For maximizing sugar recovery, post-harvest sucrose loss could be minimized by either reducing the time lag between harvest and milling or minimizing sucrose inversion by using some invertase inhibitors. Keeping above facts in view, field experiments were conducted during the year 2007 and 2008 for studying the effect of pre-harvest foliar application of divalent cation zinc as zinc sulphate (an invertase inhibitor) on post-harvest sucrose loss and internodal acid invertase activity during staling of cane. Results showed the deterioration of zinc sulphate treated cane was less in comparison to deterioration of untreated cane as revealed by significant higher commercial cane sugar (CCS %) in zinc sulphate treated trash covered cane after 1 week of staling in comparison to CCS % of control trash covered cane. Higher CCS % in zinc sulphate treated cane was due to lower enzymic inversion of sucrose because of inhibition of inter-nodal acid invertase by zinc sulphate.

Effect of Postharvest Application of Carvone on Potato Tubers Grown from True Potato Seed (TPS)

Dormancy duration is an important quality aspect of both ware and seed potato tubers and may be extended by the application of chemical sprout suppressants. The replacement of these synthetic compounds by essential oils with sprouting-inhibitory properties may contribute to the sustainable cultivation of potato.The aim of this study was to examine how the postharvest application of carvone affects potato tubers grown from true potato seed (hybrid CIP IP 88008). Ten days after harvest, tubers were placed in air-tight glass containers and carvone was applied repeatedly (300mL/1000kg tubers) while untreated tubers were used for the control. The containers were stored at 5, 10 and 20°C and opened every two days for 10minutes for aeration. The number of sprouts per tuber, rate of respiration, fresh weight loss and concentration of glucose, fructose and sucrose in tuber tissue from the buds (‘eyes’) and the parenchyma were recorded.Carvone application did not affect bud dormancy duration at 5°C and buds did not sprout even after 98 days’ storage. At 10 and 20°C, carvone application prolonged dormancy, but at 20°C a high percentage of rotted tubers (40%) was observed. At all storage temperatures, carvone reduced weight loss but increased the rate of tuber respiration. Carvone application did not affect sugar content at 5οC, but after 68 days of storage at 10οC the concentration of fructose increased and sucrose decreased. However, after 4 months of storage no differences in sugar concentration were recorded.It is concluded that carvone application can effectively prolong bud dormancy during storage at 10οC. Even though the concentration of reducing sugars and the tuber respiration rate increased, there were no negative effects on the quality aspects of tubers (concentration of glucose, fructose and sucrose) after long term storage.

Tile Drainage and Nitrogen Fertilizer Management Influences on Nitrogen Availability, Losses, and Crop Yields

Installing tile drainage facilitates early planting and field operations, and tiling has tremendously increased in the Red River Valley (RRV) due to recent wet cycles. This experiment studied tile drainage and N-fertilizer management effects on N availability, N losses, and yields of corn (Zea mays L.) and sugarbeet (Beta vulgaris L.) in a naturally poorly-drained Fargo soil during the 2012-2013 growing seasons. Regardless of drainage, applying 146 kg N ha-1 with nitrapyrin resulted similar soil N availability to 180 kg N ha-1 without nitrapyrin in sugarbeet in both years. In corn, application of nitrapyrin resulted either higher or similar soil N levels to split-N application. In 2013, application of urea alone increased soil N availability during the early corn growing season under the undrained condition, whereas nitrapyrin delayed N release in the tile-drained soils. Corn and sugarbeet yields averaged 7.4 and 47.0 Mg·ha-1 in 2012, and averaged 8.3 and 38.3 Mg·ha-1 in 2013, respectively, with no significant differences among N-sources. However, corn yield increased on an average by 27.6% with N-fertilizer application over unfertilized control in 2013. In 2012, sugarbeet root impurity (% sucrose loss to molasses) increased by 13.8% and 17.2% with 146 kg N ha-1 plus nitrapyrin and 180 kg N ha-1 treatments, respectively, compared to unfertilized control. Besides, higher N rates were usually associated with greater daily soil N2O emissions, with the maximum flux of 105 g N2O-N ha-1·d-1 recorded under corn. Addition of fertilizer-N increased NH3 volatilization losses up to 1.9% and 0.5% of the applied-N in corn and sugarbeet, respectively. Tile drainage influenced soil N availability more than crop yield during two years of study. Nitrogen management can have pronounced effects on N availability and losses. A long-term study is needed to investigate the fertilizer-N use efficiency of crops under tile drainage condition.

Identificación y cuantificación de pérdidas de sacarosa en el efluente final del proceso de elaboración de azúcar en el ingenio azucarero Riopaila Castilla (planta Castilla)

El artículo es producto del proyecto de grado titulado “Identificación y cuantificación de pérdidas de sacarosa en el efluente final del proceso de elaboración de azúcar en un ingenio azucarero” desarrollado en la Universidad Santiago de Cali. El objetivo del proyecto fue la identificación y cuantificación de pérdidas de sacarosa en el efluente de elaboración del Ingenio Riopaila Castilla, planta Castilla. El problema de investigación surgió del interés en aprovechar la gran cantidad de sacarosa que se pierde en el proceso de elaboración del azúcar con un valor aproximado de $1500 millones por año. Los resultados de investigación fueron: una disminución de pérdidas de sacarosa que posiciona al ingenio en el primer lugar con las pérdidas de sacarosa más bajas de todo el sector azucarero en Colombia; la creación de seis nuevos puestos de trabajo (inspectores de pérdidas); disminución del impacto ambiental con la reducción de sacarosa contaminante en el efluente final; y un mejor manejo en el control de la sacarosa en el efluente final.

Effect of Combined Application of Different Micronutrients on Productivity and Quality of Sugar Beet Plants (Beta vulgaris L.)

The experiments were conducted throughout two successive winter seasons 2010/2011 and 2011/2012 at Belquas, Dakahlia Governorate, Egypt. The aim of this work was to investigate the effect of foliar application with different micronutrients with excluding one element each treatment and its addition times on the productivity and quality of sugar beet plants. The treatments were six combinations of micronutrients, T0 (spraying with water),T1 (Fe+Zn+Mn+B), T2 (T1-Fe), T3 (T1-Zn), T4 (T1-Mn), T5 (T1-B) and two application times (once after 60 days from sowing or twice after 60 and 90 days from sowing) at 50ppm for each in the form of (Zinc sulphate, Manganese sulphate and Boric acid) and 100ppm in the form of Iron sulphate. Results indicated that, T1 recorded the highest values for yield characters i.e. root, top and sugar yields as well as root weight and dimensions as compared with other treatments followed by T2. Moreover, the results concluded that T1 treatment produced the maximum sucrose %, purity %, recoverable sugar % and white sugar yield followed by T2 in both seasons, this proving that Fe was the least effective microelement on productivity and quality traits of sugar beet. On the other hand, T3 and T4 recorded the lowest values of all yield and yield components and this may be due to the role of Zn and Mn in plant growth as well as their effect as metal components of some enzymes. Furthermore, Zn and B followed by Mn positively affected the impurities content i.e. K, Na and amino N % as well as sucrose loss to molasses, so

Solid state of processed carbohydrate matrices from maltodextrin and sucrose

Various mixtures of maltodextrin, sucrose, and water, as typical compounds of food matrices used for flavour encapsulation via extrusion, were processed in a batch mixing process. Plasticization, melting and caramelization just as the formation of amorphous sucrose were studied. All matrices were plasticized within 2min, resulting in a loss of crystalline sucrose. Melting occurred due to water loss higher than 55%. Caramelization could be correlated to a specific mechanical energy input higher than 300Wh/kg. The glass transition temperature of the caramelized matrices could not be fitted with the Gordon Taylor equation, based on the used compounds. Increasing sucrose content in the preblended powder mixture combined with increasing sample water content increased the crystalline fraction within the matrix. These findings enable a systematically investigation of matrices for encapsulation of flavours within the batch mixing process, which can help to transfer the flavour encapsulation to an extrusion process.

Effect of period, water temperature and agitation on loss of water-soluble carbohydrates and protein from grass hay: implications for equine feeding management

The effects of different water-soaking treatments on removal of water-soluble carbohydrates (WSC), WSC constituents and protein from four UK hays were determined. Hays were soaked in water for up to...

Assessment of Peeling of Astragalus Roots Using 1H NMR- and UPLC-MS-Based Metabolite Profiling

A metabolomic analysis was performed to examine the postharvest processing of Astragalus membranaceus roots with a focus on the peeling procedure using (1)H NMR and UPLC-MS analyses. Principal component analysis (PCA) score plots from the (1)H NMR and UPLC-MS data showed clear separation between peeled and unpeeled Astragalus roots. Peeled roots exhibited significant losses of several primary metabolites, including acetate, alanine, arginine, caprate, fumarate, glutamate, histidine, N-acetylaspartate, malate, proline, sucrose, trigonelline, and valine. In contrast, the peeled roots contained higher levels of asparagine, aspartate, and xylose, which are xylem-related compounds, and formate, which is produced in response to wound stress incurred during postharvest processing. In addition, the levels of isoflavonoids and astragalosides were significantly reduced in peeled Astragalus root. These results demonstrate that metabolite profiling based on a combination of (1)H NMR and UPLC-MS analyses can be used to evaluate peeling procedures used in the postharvest processing of herbal medicines.

Improvement in Shelf Life and Safety of Pasteurized Palm Sap (Borassus flabellifer Linn.) by the Addition of Nisin

AbstractThe objective of this study was to improve the quality and safety of pasteurized palm sap by the addition of various concentrations of nisin. The pasteurization condition was 75C for 10 min as considered from no growth of pathogens was detected while the concentrations of nisin in the range of 0–40 IU/mL were selected for addition in palm sap as considered from sensory evaluation. The initial pH of pasteurized palm sap was 6.6 and the addition of nisin caused a decrease in the pH to 6.2, 6.0, 5.8 and 5.6 for the samples added 10, 20, 30 and 40 IU/mL, respectively. The initial polyphenol oxidase activity decreased by approximately 55 and 76% for the sample without nisin added and the sample added 40 IU/mL nisin, respectively, from the original value measured in fresh palm sap while the initial invertase activity was not affected by nisin. During storage, the loss of sucrose, polyphenol content, DPPH‐RSA and the increment in browning intensity were minimized by nisin treatment, particularly at 30–40 IU/mL. The combination of pasteurization with the addition of nisin (30 IU/mL) and low temperature storage could preserve palm sap for 10 weeks whereas the control sample was spoiled within 2 weeks.Practical ApplicationsThe sale of pasteurized palm sap is a common practice in Thailand and its consumption has increased over the past years. However, pasteurized palm sap has a short shelf life (approximately 1–2 weeks). In order to control the growth of spoilage microorganisms, the use of natural antimicrobial preservatives has been preferred in the food industry. For this purpose, nisin was preferred in this study. Although there are many reports on the use of nisin to prolong the shelf life of food, research on the utilization of nisin in palm sap is limited. According to the results, the addition of nisin could reduce the pasteurization temperature and time. In addition, the use of nisin (30 IU/mL) significantly reduced spoilage microorganism counts and extended the refrigerated shelf life of pasteurized palm sap for at least 10 weeks. Therefore, the safety of pasteurized palm sap during storage could be improved by the addition of nisin. This result may be a practical application for the producer because of the short shelf life of this product.

Utilization of chitosan as an antimicrobial agent for pasteurized palm sap (Borassus flabellifer Linn.) during storage.

The objective of this research was to assess the potential of chitosan for improvement the quality of pasteurized palm sap during storage. First, the effect of chitosan content on sensory attributes was investigated to select suitable concentration of chitosan for further study. Fresh palm sap was enriched with chitosan at various concentrations (0-2g/L) and pasteurized at 80°C for 10min, consequently evaluated by consumers. It was found that samples added chitosan in the range of 0-1.00g/L were considered acceptable. Thus, the addition chitosan in the concentration of 0-1.00g/L was chosen for further study. The sample without chitosan addition was used as a control sample. Each selected sample was determined for their qualities during storage at 1week interval. It was found that lightness and transmittance values of all samples tended to increase during storage. Lower PPO and invertase activity were observed in all chitosan-treated samples compared to control sample. Chitosan could minimize the loss of sucrose and the increase in glucose and fructose content during storage. In addition, an increase in chitosan concentration resulted in the increase in DPPH radical scavenging activity. Furthermore, the addition of chitosan could retard the development of microorganism during storage as demonstrated by lower microbial loads compared to control sample. It can be concluded that a combination of pasteurization with chitosan addition (0.50g/L) and low temperature storage could preserve palm sap for approximately 6weeks. Thus, the incorporation of chitosan in palm sap could be used as an alternative way to extend shelf life of pasteurized palm sap.

Effect of temperature-controlled fermentation on physico-chemical properties and lactic acid bacterial count of durian (Durio zibethinus Murr.) pulp.

Effects of controlled-temperature fermentation on several physico-chemical properties, lactic acid bacteria (LAB) counts and aroma of durian pulp were examined by storing fresh durian pulp was mixed with 2% (w/w) salt and stored at 15°C, 27°C and 40°C for 10days. Storage at 15°C did not affect the properties of the pulp much. However, at 27°C and 40°C, pH and total soluble solids decreased up to 60% and 52%, respectively, with greater losses at 27°C. Titratable acidity, which increased at 27°C, was due to lactic and acetic acids formation. Loss of sucrose and increases in glucose were greater at 27°C. LAB population increased up to Day 3 of storage, and then decreased slightly. Principal component analysis based on aroma examination using a zNose(TM) showed better retention of aroma profile at 27°C. Overall, durian fermented at 27°C was more acceptable than the one prepared at 40°C, and it is ready to be consumed between Day 4 and 6.

Improved Control of Sucrose Losses and Clarified Juice Turbidity with Lime Saccharate in Hot Lime Clarification of Sugarcane Juice and other Comparisons with Milk of Lime

A comparative investigation of adding milk of lime (MOL) versus lime saccharate (SACCH) in the hot lime clarification of juice at a U.S. sugarcane factory was undertaken to quantify performance across the 2009 processing season, after a preliminary factory study in 2008. SACCH was prepared by adding hydrated lime to hot clarified juice (CJ) in a greater than 1:7 ratio. The lime treatment was added to flash heated limed juice (FHLJ) to obtain a target CJ pH of 7.3. Samples of FHLJ and CJ were collected six times every 30 min, taking into account the retention time of the clarification tank. Results from the preliminary study suggested that SACCH caused lower turbidity in CJs with better control, as well as higher and better controlled CJ pHs. Across the 2009 season, SACCH factory mud volumes tended to be slightly (no significant difference) higher than for MOL, but no greater than 8.5%. In 2009, CJ turbidities with SACCH were, generally, lower and better controlled than MOL. Lower median particle sizes in CJs with MOL across the season at least partially explain the higher CJ turbidities with MOL than SACCH. For the same amount of hydrated lime added, SACCH produced a higher pH than MOL and this, generally, allowed SACCH to achieve the target CJ pH better than MOL and reduce sucrose losses from acid inversion. No significantly (P < 0.05) extra lime had to be added in the SACCH than MOL treatment, and there were no significant differences between the color of either FHLJ or CJ from SACCH or MOL. Overall, the use of SACCH over MOL improved hot lime clarification especially with respect to the achievement and control of target pH values that saved a considerable amount in sucrose losses and improved turbidity values of clarified juices. Practical Applications This paper is highly practical because in recent years there has been a shift in the U.S.A. and worldwide from the harvesting of burnt to green (unburnt) sugarcane, which has meant that more sugarcane leaves and tops are being processed at factories and have made clarification and sucrose losses worse. The work represented here offers a solution to this by proving that the addition of lime saccharate (SACCH) instead of the traditional milk of lime (MOL), during clarification of sugarcane juice, can improve turbid particle removal and be used as a tool by sugar processors to reduce expensive sucrose losses. This paper reports the performance of MOL and SACCH lime treatments on both the laboratory and factory clarification of sugarcane juices and puts forward explanations for the differences observed.

Influence of postharvest storage temperature, time, and invertase enzyme activity on sucrose and weight loss in sugarcane

Sugarcane cultivars of two maturity groups, early and late were harvested in the months of March, April, May, and June 2007. The harvested sugarcanes were stored for 24, 48, 72, 96 and 120h. The average maximum and minimum atmospheric temperatures in these months were 35.5, 37.8, 39.8 and 40.9°C and 16.9, 18.4, 19.4, 20.8°C, respectively. Metabolic changes in the content of sucrose in sugarcane juice in relation to the activities of acid invertase (AI), neutral invertase (NI) enzymes, acidity, and loss in sugarcane weight were studied. Extractable sucrose percent in juice declined significantly with increasing storage periods and temperature. Activities of enzymes AI and NI showed a sharp increase during 0–120h of storage. Activities of both enzymes were significantly negatively correlated with the sucrose percent in juice. There was a rapid increase in acidity and loss in sugarcane weight during storage, and the rate was higher at higher temperatures. Significant differences in the reduction of sucrose percent in different cultivars during storage were found. These results might be helpful to minimize sucrose losses during storage of sugarcane from late harvests and for developing hybrids with improved storage properties.

EFFECT OF BOILING TREATMENTS ON BIOCHEMICAL CONSTITUENTS OF VEGETABLE-TYPE SOYBEAN

Immature seeds of four vegetable-type soybean genotypes were subjected to boiling under pressure (5 min) and at atmospheric pressure (10 min) to assess the two boiling treatments in minimizing the losses of biochemical attributes viz. isoflavones, vitamin C, sucrose and reducing the undesirable factors viz. trypsin inhibitor, lipoxygenases, raffinose and stachyose. Boiling under pressure caused significantly higher (P < 0.05) decline for daidzein and glycitein compared with the boiling at atmospheric pressure. Similarly, boiling under pressure caused significantly (P < 0.05) less vitamin C loss and higher decline of sucrose. Conversely, genistein increased because of both the boiling treatments. Both the boiling treatments equally deactivated lipoxygenases, while the boiling at atmospheric pressure was more effective in reducing trypsin inhibitor. Raffinose and stachyose was either not detected or present in negligible levels in raw seeds. Results suggest that the boiling of vegetable soybean at atmospheric pressure may be preferred to the boiling under pressure. PRACTICAL APPLICATION Immature green seeds of vegetable soybean are subjected to boiling treatment prior to consumption or storage. The information regarding the changes in the levels of biochemical constituents of vegetable soybean after boiling treatment is very limited. In the present investigation, the effects of boiling treatment under pressure and at atmospheric pressure on the levels of isoflavones, vitamin C, sucrose, lipoxygenases, trypsin inhibitor, flatulence factors of immature seeds were studied. Though there was less loss for vitamin C content because of boiling under pressure and both the boiling treatments were found equally effective for inactivating lipoxygenases, the boiling applied at atmospheric pressure appeared comparatively superior as it resulted in less isoflavones and sucrose losses and higher trypsin inhibitor reduction. The study is of practical significance for vegetable soybean industry, which requires blanched immature seeds with high levels of taste and nutraceutical components and minimum concentration of antinutritional factors for canning.

Influence of Rhizoctonia-Bacterial Root Rot Complex in Storability of Sugarbeet

A Rhizoctonia-bacterial root rot complex can lead to yield loss in the field but rots also have the potential to cause sucrose loss in storage. Thus, studies were conducted to investigate if combining sugarbeet roots suffering from this complex with healthy roots would compromise the ability of the healthy roots to retain sucrose. Over a three year period, root samples from three commercial cultivars were compared in storage as a healthy (eight healthy roots) or mixed (eight healthy roots + one rotted root) treatment inside an outdoor storage pile. The experiment was arranged as a split block (healthy in one half of block and mixed in the other) with the whole blocks arranged in a ran domized complete block design with four replications. Treatments were sampled in December, January, and February and evaluated for discolored and frozen root area, weight loss, and sucrose reduction and recovery. When comparing the healthy to the mixed treatment over the nine year x sampling date combinations, the Wilcoxon signed-rank test indicated the median change for discoloration (7% increase), frozen area (14% increase), sucrose loss (5% loss), and recoverable sucrose (689 kg/ha less or 8% reduction) were signifi cantly different from zero ( P = 0.008, 0.031, 0.007, and 0.008, respectively). These data indicate that the Rhi zoctonia-bacterial root rot complex can negatively af fect neighboring healthy roots in storage leading to additional sucrose losses.

Physico-Chemical Method of Preserving Sucrose in Harvested Sugarcane at High Ambient Temperature in a Sub-Tropical Climate

Sugarcane in subtropical areas is harvested under a wide array of temperatures, grading from 8 to 42°C. The crushing of harvested cane is often delayed for longer than 72 h leading to a steep decline in sucrose content, especially late in the harvest season when ambient temperatures are high. The average reductions in Commercial Cane Sugar (CCS) in untreated billets and whole cane during late harvest were 0.735 and 0.502 units/day. These losses were reduced to 0.310 and 0.365 units/day following treatment with a chemical formulation containing benzalkonium chloride (0.2%) and sodium metasilicate (0.5%). These chemicals also decreased the formation of reducing sugars in billets from 13.19 to 5.13 and 15.69 to 6.18 mg/ml per day in upper and lower billets, respectively. This study might be useful in minimizing post-harvest sucrose losses in sugarcane at high ambient temperature.

Sugarbeet Cultivar Evaluation for Bacterial Root Rot

Bacterial root rot of sugarbeet (Beta vulgaris) caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the Intermountain West region of the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assay for identifying host resistance. In 2006 and 2007, 21 commercial cultivars were evaluated in a petri dish laboratory assay. Root slices were inoculated with L. mesenteroides and the diameter of the rotted area was measured after 72 and 96 h. The cultivars were arranged in a randomized complete block design with 4 replications. With 2006 roots after 96 h, the average rot diameter ranged from 16 to 34 mm (LSD = 5) depending on cultivar. With 2007 roots after 96 h, the average rot diameter ranged from 10 to 48 mm (LSD = 7) depending on cultivar. The cultivar ranking between years was correlated at 72 (r = 0.47, P = 0.03) and 96 (r = 0.43, P = 0.05) h. The assay allowed for reliable cultivar separation regardless of whether one, two, three, or four roots were used per replication. The laboratory assay has the potential to allow host resistance to bacterial root rot caused by L. mesenteroides to be improved in sugarbeet.

Effect of Saccharicoccus sacchari (Cockerell) infestation levels on sugarcane physical and chemical properties

The present investigation was carried out in Sohage Governorate, Egypt on sugarcane infested with Saccharicoccus sacchari (Cockerell) (Hemiptera: Pseudococcidae) during growing year 2007/2008. Obtained results indicated that only sever infestation significantly affected sugarcane physical and chemical properties. There were reduction of stalk's weight (5.03, 34.33%), stalk's height (2.16, 6.93%), stalk internodes' number per stalk (8.8, 29.07) and juice weight (2.26, 31.62%) in low and heavy Infestation, respectively compared with infestation free. Internodes height increased by 8.59 and 35.45% due to low and sever levels of infestation, respectively. There were losses of brix (4.95, 13.47%), sucrose (6.29, 27.87%), purity (1.41, 16.87%), pol (5.29, 32.6%) and sugar recovery (5.29, 37.08%) and increase of reducing sugar (3.53, 7.68%) and fiber (1.28, 3.85%) due low and heavy levels of infestation, respectively.

Quality attributes of vegetable soybean as a function of boiling time and condition

SummaryVegetable soybeans are marketed fresh or frozen, either shelled or in pods. The objective of this research was to characterise the change in quality attributes of vegetable soybean with boiling time (0–20 min), and presence/absence of pods, using an electrical‐resistance stove or a steam‐jacketed kettle. Trypsin inhibitor activity (TIA), texture, colour, soluble sugars, nitrogen, calcium and iron content were analysed. Blanching using a steam‐jacketed kettle for approximately 2 min rendered 80% inactivation of TIA, and resulted in high colour, texture and sucrose. There were no differences between blanching in pods or shelled for TIA, colour and texture; however, blanching in pods prevented losses of sucrose. Blanching did not affect iron, mono‐ and oligosaccharide levels, but increased nitrogen and calcium content. Additionally, we observed that all traits decreased linearly with cooking time when using an electrical‐resistance stove, except for calcium and nitrogen that increased, and oligosaccharides that remained constant.