Lower Reducing Sugar Content Research Articles

Engineering in the Production of Crystal Coconut Sugar Enriched with Vitamin A and its Preference Tests for Consumers

Coconut sugar is a food product that has the potential to be fortified with Vitamin A. This study aims to assess the quality of crystalline coconut sugar with vitamin A and test its preference for consumers. The experimental design used Split Plot Design with two treatment factors and 4 replications. The first treatment as the Main Plot (Main Plot) is the type of raw material for crystalline coconut sugar, which consists of 2 variations, namely: M1 = pure sap, and M2 = printed coconut sugar + 5% granulated sugar. The second treatment as a sub-plot was the proportion between palm oil as a solvent and carrots as a source of carotene (Vitamin A), which consisted of 3 variations, namely: S1= 1 : 1 (v/b), S2 = 1 : 2 (v/b), and S3= 2 : 1 (v/b). Physicochemical data were analyzed by F test and followed by 5% DMRT test, while organoleptic properties data were analyzed by Friedman test and followed by multiple comparison test. The best treatment was analyzed by the effectiveness index method. The results showed that a good raw material for producing crystalline coconut sugar with low reducing sugar content and high sucrose content was pure coconut sap. The proportion between palm oil and carrots which can produce crystalline coconut sugar with high levels of carotene (pro vitamin A) is 1 : 2 (v/b). The treatment combination that can produce crystalline coconut sugar with vitamin A with quality according to SNI-SII No.0268-85 is the treatment of the type of raw material for crystalline coconut sugar from pure coconut sap and the proportion of palm oil as a solvent with carrots as a source of carotene 1 : 2 ( v/b). This combination of treatments produced crystalline coconut sugar with physicochemical and organoleptic properties as follows: carotene content of 9.015 mg/100g of material or the equivalent of 752 RE (Retinol equivalent), water content of 3.617 percent, total sugar content of 81.071 percent, sucrose content of 75.627 percent, sugar content 5.434 percent reduction, 0.753 percent ash content and 0.197 percent water insoluble material content, "very smooth" texture, "creamy" color, "strong" coconut aroma, "not felt" carrot unpleasant smell and level of consumer acceptance (preference) "like".

Effect of microwave radiation combined with cellulase treatment of soybean residue on the culture of Aspergillus oryzae

Soybean residue (SR) is a by-product of bean product processing with potential usefulness as a fermentation medium. However, the fermentation efficiency of SR is limited due to its low reducing sugar content. In this study, a method of microwave radiation combined with cellulase hydrolysis (MCH) was developed to increase the reducing sugar content of SR, and the effect of treated SR on fermentation by Aspergillus oryzae was evaluated. First, the process parameters, including the reaction time, pH and temperature, were optimized. Second, the effect of treated SR on fermentation by A. oryzae was evaluated, including changes in cell proliferation and protease viability. The results showed that the MCH method capitalized on the advantages of microwave radiation and cellulase and promoted the enzymatic hydrolysis of fibrous polysaccharides in the crystallization zone of SR. The reducing sugar content of SR significantly increased from 0.42 to 0.98 mg/mL after MCH treatment. In addition, treated SR effectively promoted the proliferation of A. oryzae, and the protease activity reached 111 U/mL after 3 days of fermentation. The results of this study suggested that the MCH method can effectively increase the reducing sugar content of SR to expand its use as a fermentation medium.

Suppression of the tonoplast sugar transporter StTST3.2 improves quality of potato chips

Which sugar transporter regulates sugar accumulation in tubers is largely unknown. Accumulation of reducing sugar (RS) in potato (Solanum tuberosum L.) tubers negatively affects the quality of tubers undergoing the frying process. However, little is known about the genes involved in regulating RS content in tubers at harvest. Here, we have identified two tonoplast sugar transporter (TST) 3-type isoforms (StTST3.1 and StTST3.2) in potato. Quantitative real-time PCR results indicate that StTST3.1 and StTST3.2 possess distinct expression patterns in various potato tissues. StTST3.2 was found to be the expressed TST3-type isoform in tubers. Further subcellular localization analysis revealed that StTST3.2 was targeted to the tonoplast. Silencing of StTST3.2 in potato by stable transformation resulted in significantly lower RS content in tubers at harvest or after room temperature storage, suggesting StTST3.2 plays an important role in RS accumulation in tubers. Accordingly, compared with the unsilenced control, potato chips processed from StTST3.2-silenced tubers exhibited lighter color and dramatically decreased acrylamide production at harvest or after room temperature storage. In addition, we demonstrated that silencing of StTST3.2 has no significant effect on potato growth and development. Thus, suppression of StTST3.2 could be another effective approach for improving processing quality and decreasing acrylamide content in potato tubers.

Eliminating protein interference when quantifying potato reducing sugars with the miniaturized Somogyi-Nelson assay

Reducing sugar (RS) quantification is essential in the potato industry because RS content plays a vital role in potato quality, acrylamide formation, post-harvest management, and new variety development. A miniaturized Somogyi-Nelson (SN) analysis can effectively and accurately quantify RS. However, soluble proteins in potatoes interfere with SN analysis. Our research goal was to develop an applicable deprotinization procedure without influencing the precision of the SN analysis. Results showed ethanol effectively removed potato proteins and, unlike other chemicals (salts, acids), ethanol did not affect SN accuracy. Protein removal also can be achieved by heating and pH adjustment, but the ethanol-based procedure provides a simpler alternative. RS content measured by the miniaturized SN assay after deproteinization by ethanol was precise and validated by HPAEC-PAD. Data from 118 potao juicies showed that a commonly used biochemical analyzer obtained a lower reducing sugar content than the deprotinization-SN assay because fructose was not identified by the biochemical analyzer. Results demonstrate the reliability of quantifying potato RS with the SN assay following the ethanol-based deproteinization.

Effect of aeration on the growth and sporulation of Aspergillus niger in cassava stalks bioconversion

Aspergillus niger is a mould which can be used in bioconversion of cassava stalks through solid-state fermentation. Mould is aerobic microorganism and require oxygen for their growth. Sufficient supply of oxygen by aeration will give better growth of mold, but excess of oxygen will act as a bad condition and encourage production of spores. Moulds at sporulation stage will not produced enzymes required for bioconversion of lignocellulosic material, for example cassava stalks. The aim of this study was to know effect of aeration on the growth and sporulation of Aspergillus niger in bioconversion of cassava stalks. Aspergillus niger FNCC 6114 were grown on media of cassava stalks powder moistened with water in 1:1 ratio, incubated inside of two kinds of incubators. The first, incubator of plastic box at 20 L capacities without aeration. The second, incubator equipped with aquarium aerator for force-aeration and IV needles for controlling the speed of aeration at 40 mL/min. Based on the result, it was shown that fermented media from aerated incubator were: higher glucosamine content, lower reducing sugar content, and higher spores quantity. These indicated that aeration at the speed of 40 mL/min will encourage growth and increase sporulation of Aspergillus niger FNCC 6114.

Impacts of different blanching pretreatments on the quality of dried potato chips and fried potato crisps undergoing heat pump drying

Abstract Hot water blanching (WB) and steam blanching (SB) have been noted to improve the quality of potato chips. In this work, the possibility of steam blanching assisted with ultrasound treatment (SUB) to enhance the quality of dried potato chips and fried potato crisps was investigated. Compared to WB and SB groups, dried potato chips of SUB groups showed lower shrinkage ratio (78.46%), higher rehydration capability (3.93:1), and lower moisture content (0.08 g/g). Meanwhile, fried potato crisps of SUB groups displayed lower hardness (1965.70 g) and oil content (12.0%). The low reducing sugar content (0.42%) and free amino acid content (6.10 mg/g) in SUB dried potato slices could explain for the higher L * value, lower a * and ΔE values of SUB fried potato crisps. Additionally, sensory evaluation results confirmed above obtained consequences. Overall, SUB could improve the quality of fried potato crisps further in comparison with WB and SB.

Evaluation of potato genotypes for french fry quality

Nine potato genotypes viz. ‘Kufri Chipsona-1’, ‘Kufri Chipsona-3’, ‘Kufri Frysona’, ‘MS/7–645’, ‘MP/04 578’, ‘MP/4–816’, ‘MS/8–1148’, ‘LR’ and ‘J/2–19’ were evaluated to find out their suitability for processing into French fries. All the French fry quality attributes varied with genotype. Genotypes, ‘Kufri Frysona’, ‘MP/04–578’ and ‘MP/4–816’ were rated the best for processing into French fries, since these genotypes possessed desirable tuber shape (oblong) and length (7.90–10.20 cm), high dry matter (19.06–21.61%) and low reducing sugar content (0.03–0.06%). These genotypes may also be considered good for vegetable consumption because of higher amounts of total phenolics and antioxidant activity compared to other genotypes. Other genotypes, ‘Kufri Chipsona-1’ and ‘LR’ were found to be suitable for potato crisps processing due to chipping quality traits such as tuber shape (round), length (6.17.70cm) and high average dry matter (23.30%) and low reducing sugars (0.03%).

Dispersion‐assisted extraction of guarana processing wastes on the obtaining of polyphenols and alkaloids

AbstractThis is the first work to evaluate the effects of high shear mixing (HSM) on the recovery of valuable polar compounds from guarana processing wastes (peels and depleted seeds), which results may server to support researches on the valorization of guarana. Under the optimum condition, the HSM was led to extract catechin (11.11–42.93 g/100 g raw material), epicatechin (7.83–24.78 g/100 g raw material) and caffeine (9.99–28.80 g/100 g raw material) from guarana products, which contents were comparable with those obtained with ultrasound assisted extraction and maceration, and significantly higher than those obtained with infusion and decoction. Besides the relatively low reducing sugar content (0.02–0.23 g glucose equivalent/100 g raw material), HSM extracts also presented high antioxidant capacity (25–533 mg ascorbic acid equivalent/g raw material) and phenolic compounds (0.5–45 g catechin equivalent/100 g raw material and 0.1–66.38 g gallic acid equivalent/100 g raw material). The use of pectinase enhanced the HSM to recover target compounds in depleted seeds.Practical applicationsThe use of guarana has emerged as a source of antioxidants, associated to enhancement of cognitive function, to prevent cancer‐related symptoms, and to control the weight. This paper is the first research to use high‐shear mixing (HSM) to maximize the recovery of bioactive compounds from the peels and depleted seeds of guarana, the wastes derived from the Brazilian carbonated beverage industry. The extraction efficiency of HSM for 1 min to recover polyphenols and alkaloids was like those of ultrasound assisted assisted and maceration, performed for 30 min. Our results confirm that HSM is an environmentally friendly, rapid and low‐cost method to extract bioactive compounds from guarana. Our results are expected to support further researches on the use of HSM as an extraction protocol for analysis and to evaluate the multipurpose potential of guarana processing wastes for food and non‐food formulations.

시판 효모의 종류를 달리한 약주의 품질특성

This study was conducted to investigate the characteristics of Yakju fermented using different 7 commercial yeasts; La parisienne (black), La parisienne (red), Fermivin, RC212, K1-V1116, D47, and EC1118. After completion of fermentation, the total acid content in Yakju ranged from 0.26 to 0.40%; the lowest and highest values corresponded to fermentation using La parisienne (red) and EC1118, respectively. The amino acidity of the different Yakju samples varied significantly in the range of 2.49 to 5.50. The Yakju fermented with K1-V1116, La parisienne (black), La parisienne (red) showed high amino acidity levels of 5.59, 5.55 and 5.34, respectively, but that fermented with Fermivin showed a low level of 2.49. EC1118 seemed to be most suitable for producing the dry type of alcoholic beverage because of the low reducing sugar content (0.19%) and soluble solid (7.2 °Brix). The main organic acids in Yakju were succinic acid, lactic acid, citric acid, malic acid and acetic acid. Further, the succinic acid content in Yakju fermented with La parisienne (black), La parisienne (red) was high (about 1,080 mg/L). The main volatile compounds were acetaldehyde, acetic acid and iso-amyl alcohol, and the acetaldehyde and acetic acid contents of the different Yakju samples varied substantially.

Iron Supply Affects Anthocyanin Content and Related Gene Expression in Berries of Vitis vinifera cv. Cabernet Sauvignon.

Anthocyanins are important compounds for red grape and red wine quality, and can be influenced by supply of nutrients such as nitrogen, phosphorus, potassium, zinc, and iron. The present work aims to gain a better understanding of the effect of iron supply on anthocyanins concentration in grape berries. To this end, own-rooted four-year-old Cabernet Sauvignon grapevines (Vitis vinifera) were fertigated every three days with 0, 23, 46, 92, and 184 μM iron (Fe) from ferric ethylenediamine di (o-hydroxyphenylacetic) acid (Fe-EDDHA) in a complete nutrient solution. Fe deficiency or excess generally led to higher concentrations of titratable acidity and skin/berry ratio, and to lower reducing sugar content, sugar/acid ratio, pH, berry weight, and concentration of anthocyanins. Most of the individual anthocyanins detected in this study, except cyanidin-3-O-glucoside, delphinidin-3-O-glucoside, and cyanidin-3-O-(6-O-coumaryl)-glucoside, in moderate Fe treatment (46 μM) grapes were significantly higher than those of other treatments. Genes encoding chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), leucoanthocyanidin dioxygenase (LDOX), and anthocyanin O-methyltransferase (AOMT) exhibited higher transcript levels in berries from plants cultivated with 46 μM Fe compared to the ones cultivated with other Fe concentrations. We suggest that grape sugar content, anthocyanins content, and transcriptions of genes involved in anthocyanin biosynthesis were correlated with Fe supply concentrations.

Development of Sustainable Gross National Income from Potato Export in Bangladesh- A Perspective Review

Potato (Solanum tuberosum L.) in Bangladesh has arisen fast due to economic liberalization coupled with growing urbanization, expanding market options. The potato is considered to be a potential crop to face the challenge of 21st century. It can serve the food security of the ever growing population, creation of job opportunities and developing agro-based and agro-processing industries in the country for sustainable economic growth. Bangladesh achieved a remarkable success in potato production to take it to 7th rank in the world map. Potato production is increasing day by day both vertically and horizontally. In 2014, total production was 8.6 million tons and the consumption capacity was 6.5 million tons, rest 2.1 million tons was surplus. So need to export potato to foreign countries. But the major constraints for this is non-availability of sufficient suitable varieties with high dry matter (>21%) and low reducing sugar content (<0.01%). Identification of cropping zones, technology packages for production of export quality varieties, non-availability of resistant varieties for bacterial wilt and technologies for long period storage are other limitations in developing export sectors in the country. To meet the instant need of the processing varieties, the variety introduction procedure may be liberalized under a crush programme to ensure quick inflow of processing varieties in the country. Export of potatoes is an important avenue to expand utilization of potatoes grown in the country.

Heatless synthesis of well dispersible Au nanoparticles using pectin biopolymer

Due to its potency to utilize in enormous applications, preparation of nanogold is of interest. Moreover, getting of highly dispersed nanogold with small size is extremely needful in specific fields. Herein, Au nanocolloid was prepared using alkali catalyzed pectin biopolymer. Pectin was concurrently used as reductant for Au ions and stabilizer for the produced Au nanoparticles (AuNPs). Reducing sugars were evaluated in the colloidal solution reflecting the role alkali in catalytic degradation of pectin to produce much powerful reducing moieties. The obtained Au nanocolloid was monitored via changing in color, UV⿿visible spectral and transmission electron microscopy. Using of NaOH as strong alkali achieving rapid rate of degradation reaction, resulted in 0.45g/L reducing sugars from 0.2g/L pectin which produced AuNPs with mean size of 6.5nm. In case of Na2CO3 which attained slow degradation rate led to, slightly low reducing sugar content (0.41g/L), fabricated comparatively size of AuNPs (7.5nm). In both cases, well distributed AuNPs was obtained with suitable stabilization up to 5 months and Na2CO3 exhibited higher stability. The current successful method used to produce small sized AuNPs with high dispersion is an innovative, one-step, easily, costless, energy saving and eco-friendly method.

Effect of extracts of wastewater from olive milling in postharvest treatments of pomegranate fruit decay caused by Penicillium adametzioides

Nonclimateric pomegranate (Punica granatum L.) fruit harvested at full ripening are susceptible to attack by different genera of pathogenic fungi such as Alternaria, Aspergillus, Botrytis, Colletotrichum, Coniella, Nematospora, Penicillium, Pestalotiopsis, Pilidiella, Rhizopus and Syncephalastrum which can cause rot of the fruits thus compromising their organoleptic and nutritional value. Seven fungal species belonging to the genus Penicillium such as Penicillium expansum, Penicillium herquei, Penicillium implicatum, Penicillium glabrum, Penicillium minioluteum, Penicillium purpurogenum and Penicillium sclerotiorum have been previously identified as causal agents of postharvest pomegranate decay. Based on culture characteristics, molecular analyses on internal transcribed spacers, β-tubulin gene sequences, and pathogenicity tests, Penicillium adametzioides S. Abe ex G. Sm. is identified as a causal agent of pomegranate fruit rot. To the best of our knowledge, this is the first report of P. adametzioides as a pathogen of P. granatum. A phenolic concentrate obtained from olive-mill wastewater through a membrane filtration process, and its related purified phenolic extract that has a lower reducing sugar content, were produced and tested in vitro and in vivo against P. adametzioides. Both the phenolic concentrate and the purified phenolic extract significantly reduced mycelial growth and conidial germination of P. adametzioides when applied at 4mgmL−1 and 8mgmL−1 phenols. At the same content of phenols, the greater reduction of mycelial growth by the purified phenolic extract was related to its lower sugar content. Of note, the purified phenolic extract at 4 and 8mgmL−1 phenols protected pomegranate fruit in vivo against P. adametzioides. Postharvest application of such by-products of the olive-oil industry might represent an alternative use of olive-mill wastewater, where its high content of phenols results in a disposal problem. This olive-mill wastewater also represents an alternative means for safe disease control of pomegranate fruit.

Enzymatically hydrolysed, acetylated and dually modified corn starch: physico-chemical, rheological and nutritional properties and effects on cake quality.

Corn starch was treated by enzymatic hydrolysis with Aspergillus oryzae S2 α-amylase, acetylation with vinyl acetate, and dual modification. The dual modified starch displayed a higher substitution degree than the acetylated starch and lower reducing sugar content than the hydrolysed starch. The results revealed that the cooling viscosity and amylose content of those products decrease (P<0.05). An increase in moisture, water, and oil absorption capacity was observed for the acetylated starch and, which was less pronounced for the enzymatically hydrolysed starch but more pronounced for the enzymatically hydrolysed acetylated product. The latter product underwent an increase in resistant starch content, which is induced by a rise in hydrolysis time to attain about 67% after 1h of reaction. The modified starch samples were added to cake formulations at 5 and 10% concentrations on a wheat flour basis and compared to native starch. The results revealed that when applied at 5% concentrations, the modified starches reduced the hardness, cohesion, adhesion and chewiness of baked cakes and enhanced their elasticity, volume, height, crust color, and appearance as compared to native starch. These effects were more pronounced for the cake incorporating the dually modified starch.

전통적인 방법으로 제조된 된장 제품의 이화학적 및 관능적 특성에 대한 연구

To study traditional Doenjang characteristics, Doenjang was purchased from five different provinces: Chungcheong (CC), Gangwon (GW), Gyeonggi (GG), Gyeongsang (GS), and Jeolla (JL). To determine physicochemical characteristics, contents of reducing sugar, amino type nitrogen, salt, pH, and acidity were analyzed. The sensory characteristics were analyzed by sensory descriptive analysis. Reducing sugar content was highest for Doenjang from GW province. Amino type nitrogen content was highest for Doenjang from JL province. The salt content was highest in Doenjang from CC and GS provinces. After principal component analysis (PCA) based on sensory descriptive analysis, salty taste and aftertaste were highly correlated with overall acceptance. In the correlation analysis among chemical compounds and overall acceptance, Doenjang contained low reducing sugar content, and high pH value was positively correlated with overall acceptance. In conclusion, Doenjang with high pH value and salty taste and aftertaste have high overall acceptance.

Acrylamide reduction in potato chips by selection of potato variety grown in Iran and processing conditions

Acrylamide as a possible carcinogen is known to form in heated carbohydrate-rich food such as potato chips. In this study, the effect of three potato varieties (Agria, Sante and Savalan) and two blanching conditions (75 °C for 9 min and 83 °C for 2.5 min) on the concentration of precursors and acrylamide reduction in potato chips was investigated. Results revealed that potato variety and blanching time-temperature were important parameters for acrylamide formation in potato chips. Acrylamide content in Sante variety potatoes, which contained the highest amount of reducing sugars, was found to be the highest (8825 µg kg(-1)). However, Savalan, containing the highest asparagine concentration, showed the lowest amount of acrylamide due to its lower reducing sugar content. Blanching reduced acrylamide formation; it was more efficient at 75 °C for 9 min, with an average reduction of 74%. The effect of three frying temperatures (170, 180 and 190 °C) on acrylamide formation was also studied just for the Agria potato variety. Increasing frying temperature led to a significant increase in acrylamide formation. Potato variety and processing conditions were important parameters for acrylamide formation in potato chips. The combination of a suitable variety and appropriate processing conditions could considerably reduce acrylamide content.

Systematic analysis of potato acid invertase genes reveals that a cold-responsive member, StvacINV1, regulates cold-induced sweetening of tubers

Acid invertase is believed to play a regulatory role during plant developmental processes and to respond to environmental stimuli. The expression profiles of the entire acid invertase family are not yet available for potato. By searching existing databases, it was determined that there are at least six acid invertase genes in potato, including four cell-wall invertase genes and two vacuolar invertase genes. They were subjected to comparative expression profiling in various organs of potato plants and in stored tubers to exploit their potential functions. The results revealed that each gene exhibited a unique expression pattern, which differed in transcript abundance or showed organ-specific features, pointing to the possible involvement of individual genes in plant development. The vacuolar invertase gene StvacINV1 had the highest expression level among three genes detected in the potato tubers. Further storage experiments showed that StvacINV1 was strongly induced by low temperatures, which is consistent with glucose accumulation in cold-stored tubers. Suppression of StvacINV1 by the antisense transformation in potato confirmed that lower StvacINV1 transcript abundance in transgenic tubers is related to lower reducing sugar content and lighter chip color in comparison with the wild type. The evidence strongly suggests that StvacINV1 is a gene involved in regulation of cold-induced sweetening of potato tubers. This provides an avenue for studying the mechanism involved in the regulation of the cold-induced sweetening trait and for agronomic enhancement.

Adding value to hard date ( Phoenix dactylifera L.): Compositional, functional and sensory characteristics of date jam

Second-grade dates (with a hard texture) from three potential Tunisian cultivars (Deglet Nour, Allig and Kentichi) showed the same sugar (∼73.30–89.55 g/100 g dry matter), fibre (∼7.95–18.83 g/100 g dry matter) and total phenolics (∼280.6–681.8 mg of GAE/100 g) content as dates of high quality. Deglet Nour and Kentichi varieties were characterised by a high content of sucrose and low reducing sugar content; contrary to Allig and the majority of other date varieties tested. This work intended to add value to these raw materials by using them in jam production. The corresponding jams were characterised in terms of chemical composition, physical (texture and water retention capacities) and sensory properties. Results showed a significant effect of the date variety on the composition and physical characteristics of date jams. Indeed, Allig jam was richer in reducing sugars and was characterised by its higher firmness and water retention capacity. To test the acceptability of these new products, we compared them with quince jam (the most consumed in Tunisia). Results showed that Allig and Kentichi jams presented a higher overall acceptability. However, quince and Deglet Nour jams did not show any significant differences ( P > 0.05). Results from this work revealed essential information that could promote the commercialization of dzate jam.

Comparison of potato varieties between seasons and their potential for acrylamide formation

AbstractBACKGROUND: Acrylamide is a probable human carcinogen produced during food preparation, including frying of potato products. The aim of this study was to investigate the impact of seasonal variation on tuber composition and its acrylamide generation potential.RESULTS: The chemical composition of potato varieties used respectively for French fry (Bintje and Ramos) and crisp (Lady Rosetta and Saturna) production was studied throughout a storage period of 9 months during two growing seasons (2003 and 2004), in addition to their acrylamide generation potential during preparation of French fries. A significant impact of variable climatological conditions on the reducing sugar, dry matter, total free amino acid and free asparagine contents of tubers was observed. Exceptionally warm summers gave rise to a lower reducing sugar content (expressed on a dry matter basis) and thus a lower susceptibility to acrylamide generation during frying.CONCLUSION: It cannot be excluded that potato growers and the potato‐processing industry are confronted with some harvests that are more prone to acrylamide generation than others owing to climatological variability, thus confirming the importance of a multifactorial approach to mitigate acrylamide generation in potato products. Copyright © 2007 Society of Chemical Industry

The Canon of Potato Science: 33. Haulm Killing

Harvesting can only be done successfully when the tubers have reached a certain level of maturity. Maturation of tubers improves skin set thus improving the resistance to scuffing and skinning, increases resistance to bruising and other types of damage during harvesting and handling, and prolongs storage life by decreasing storage decay and reducing water loss during storage. More mature tubers also have a higher starch content and lower reducing sugar content than less mature tubers. In many potato growing areas the potato crop does not senesce naturally and tubers do not mature naturally, but growers destroy the crop when it is still partly green and tubers are still growing. So, tuber maturation is artificially induced by killing the haulm. Killing potato vine (haulm) is usually done 10−25 days prior to harvesting the potato tubers, although in some cases it is done only a few days before harvesting. Green-crop harvesting also does occur under very specific conditions or in a two-step approach where vine removal and lifting is followed by a short phase of storage in the field under a thin layer of soil after which the tubers are collected. Crops approaching maturity require less time for skin set than crops which are still in full production. This means that the time between haulm killing and harvesting can be shorter when the haulm killing is done in a more mature crop.