Dietary intake and food sources of choline in European populations.

Choline is an important nutrient for humans. Choline intake of the European population was assessed considering the European Food Safety Authority European Comprehensive Food Consumption Database and the United States Department of Agriculture Nutrient Database. Average choline intake ranges were 151-210 mg/d among toddlers (1 to ≤3 years old), 177-304 mg/d among other children (3 to ≤10 years old), 244-373 mg/d among adolescents (10 to ≤18 years old), 291-468 mg/d among adults (18 to ≤65 years old), 284-450 mg/d among elderly people (65 to ≤75 years old) and 269-444 mg/d among very elderly people (≥75 years old). The intakes were higher among males compared with females, mainly due to larger quantities of food consumed per day. In most of the population groups considered, the average choline intake was below the adequate intake (AI) set by the Institute of Medicine in the USA. The main food groups contributing to choline intake were meat, milk, grain, egg and their derived products, composite dishes and fish. The main limitations of this study are related to the absence of choline composition data of foods consumed by the European population and the subsequent assumption made to assess their intake levels. Given the definition of AI, no conclusion on the adequacy of choline intake can be drawn for most European population groups. Such results improve the knowledge on choline intake in Europe that could be further refined by the collection of choline composition data for foods as consumed in Europe.

Nutritional safety and suitability of a specific protein hydrolysate derived from a whey protein concentrate and used in an infant formula and follow-on formula manufactured from hydrolysed protein by FrieslandCampina Nederland B.V.

The European Commission asked EFSA to deliver an opinion on the nutritional safety and suitability of a specific protein hydrolysate. It is derived from a whey protein concentrate and used in an infant and follow-on formula manufactured by FrieslandCampina Nederland B.V., which submitted a dossier to the European Commission to request an amendment of Regulation (EU) 2016/127 with respect to the protein sources that may be used in the manufacture of infant and/or follow-on formula. The protein hydrolysate under evaluation is sufficiently characterised with respect to the fraction of the hydrolysed protein. In the pertinent intervention study provided, an infant formula manufactured from the protein hydrolysate with a protein content of 2.4 g/100 kcal and consumed as the sole source of nutrition by infants for 3 months led to a growth equivalent to a formula manufactured from intact cow's milk protein with a protein content of 2.1 g/100 kcal. Data on gastrointestinal tolerance of the formula did not raise any concerns. No experimental data have been provided on the nutritional safety and suitability of this protein source in follow-on formula. Given that it is consumed with complementary foods and the protein source is nutritionally safe and suitable in an infant formula that is the sole source of nutrition of infants, the Panel considers that the protein hydrolysate is also a nutritionally safe and suitable protein source for use in follow-on formula. The Panel concludes that the protein hydrolysate under evaluation is a nutritionally safe and suitable protein source for use in infant and follow-on formula, as long as the formula in which it is used contains a minimum of 2.4 g/100 kcal protein and complies with the compositional criteria of Regulation (EU) 2016/127 and the amino acid pattern in its Annex IIIA.

Conversion of calcium-l-methylfolate and (6S)-5-methyltetrahydrofolic acid glucosamine salt into dietary folate equivalents.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the conversion of calcium-l-methylfolate and (6S)-5-methyltetrahydrofolic acid glucosamine salt (collectively called 5-MTHF hereafter) into dietary folate equivalents (DFE). Following a systematic review, the conclusions of the opinion are based on one intervention study in adults for intakes < 400 µg/day and three intervention studies in adults for intakes ≥ 400 µg/day. At intakes below 400 µg/day, folic acid (FA) is assumed to be linearly related to responses of biomarkers of intake and status and is an appropriate comparator for deriving a DFE conversion factor for 5-MTHF. It is proposed to use the same factor as for folic acid for conversion of 5-MTHF into DFE for intakes < 400 µg/day. As such intake levels are unlikely to be exceeded through fortified food consumption, the conversion factor of 1.7 relative to natural food folate (NF) could be applied to 5-MTHF added to foods and to food supplements providing < 400 µg/day. At 400 µg/day, 5-MTHF was found to be more bioavailable than folic acid and a conversion factor of 2 is proposed for this intake level and for higher intakes. The derived DFE equations are DFE = NF + 1.7 × FA + 1.7 × 5-MTHF for fortified foods and food supplements providing intakes < 400 µg/day; and DFE = NF + 1.7 × FA + 2.0 × 5-MTHF for food supplements providing intakes ≥ 400 µg/day. Although this assessment applies to calcium-L-methylfolate and 5-MTHF glucosamine salt, it is considered that the influence of the cation on bioavailability is likely to be within the margin of error of the proposed DFE equations. Therefore, the proposed equations can also be applied to 5-MTHF associated with other cations.

Nutritional safety and suitability of a specific protein hydrolysate derived from whey protein concentrate and used in an infant and follow-on formula manufactured from hydrolysed protein by HIPP-Werk Georg Hipp OHG (dossier submitted by meyer.science GmbH).

The European Commission asked EFSA to deliver an opinion on the nutritional safety and suitability of a specific protein hydrolysate. It is derived from whey protein concentrate and used in infant and follow-on formula by HIPP-Werk Georg Hipp OHG. The dossier that was submitted to the European Commission aimed at requesting an amendment of Regulation (EU) 2016/127 with respect to the protein sources that may be used in infant and/or follow-on formula. This opinion does not cover the assessment of the safety of the food enzymes used in the manufacture of the protein hydrolysate. The protein hydrolysate under evaluation is sufficiently characterised with respect to the fraction of the hydrolysed protein. In the pertinent intervention study provided, an infant formula manufactured from the protein hydrolysate with a protein content of 1.9 g/100 kcal and consumed as the sole source of nutrition by infants for 3 months led to growth equivalent to a formula manufactured from intact cow's milk protein with the same protein content. No experimental data have been provided on the nutritional safety and suitability of this protein source in follow-on formula. However, given that it is consumed with complementary foods and the protein source is considered nutritionally safe and suitable in an infant formula that is the sole source of nutrition of infants, the Panel considers that the protein hydrolysate is also a nutritionally safe and suitable protein source for use in follow-on formula. The Panel concludes that the protein hydrolysate under evaluation is a nutritionally safe and suitable protein source for use in infant and follow-on formula, as long as the formula in which it is used contains a minimum of 1.9 g/100 kcal protein and complies with the compositional criteria of Commission Delegated Regulation (EU) 2016/127 and the amino acid pattern in its Annex IIIA.

Statement on safety of cannabidiol as a novel food: data gaps and uncertainties.

The European Commission has determined that cannabidiol (CBD) can be considered as a novel food (NF), and currently, 19 applications are under assessment at EFSA. While assessing these, it has become clear that there are knowledge gaps that need to be addressed before a conclusion on the safety of CBD can be reached. Consequently, EFSA has issued this statement, summarising the state of knowledge on the safety of CBD consumption and highlighting areas where more data are needed. Literature searches for both animal and human studies have been conducted to identify safety concerns. Many human studies have been carried out with Epidyolex®, a CBD drug authorised to treat refractory epilepsies. In the context of medical conditions, adverse effects are tolerated if the benefit outweighs the adverse effect. This is, however, not acceptable when considering CBD as a NF. Furthermore, most of the human data referred to in the CBD applications investigated the efficacy of Epidyolex (or CBD) at therapeutic doses. No NOAEL could be identified from these studies. Given the complexity and importance of CBD receptors and pathways, interactions need to be taken into account when considering CBD as a NF. The effects on drug metabolism need to be clarified. Toxicokinetics in different matrices, the half-life and accumulation need to be examined. The effect of CBD on liver, gastrointestinal tract, endocrine system, nervous system and on psychological function needs to be clarified. Studies in animals show significant reproductive toxicity, and the extent to which this occurs in humans generally and in women of child-bearing age specifically needs to be assessed. Considering the significant uncertainties and data gaps, the Panel concludes that the safety of CBD as a NF cannot currently be established.

Food and nutrient intakes of French frequent seafood consumers with regard to fish consumption recommendations: results from the CALIPSO study.

Besides providing n-3 fatty acids with nutritional and health benefits, seafood consumption may contribute to the reduction of nutrient prevalences of inadequacy. To evaluate the contributions of seafood and other food groups to nutrient intakes of frequent seafood consumers, food consumption was evaluated through an FFQ on 991 French men and women (18-81 years) consuming seafood at least twice a week. Intakes, prevalence of inadequacies, risks of upper limit excess and food contributions to intakes were assessed for thirty-three nutrients. Mean fat contributions to total energy intakes (38·3 and 39·0 % for men and women, respectively) met French recommendations, but mean carbohydrate intakes (40·9 and 39·7 %, respectively) were insufficient. Micronutrient inadequacies were lower than in the French general population, the highest being for vitamin C (41·3 and 40·1 % for men and women, respectively), vitamin E (35·0 and 35·3 % for men and women, respectively) and Mg (37·5 and 25·5 % for men and women, respectively). Upper safety limits (USL) were exceeded mostly for Zn (6·2 %), Ca (3·7 %), retinol (2·0 %) and Cu (0·9 %). Mean contributions of seafood to vitamin D, B12, I and Se intakes ranged 40-65 %. Molluscs and crustaceans significantly contributed to vitamin B12 (13·7 %), Cu (11·4 %), Fe (11·5 %), Zn (8·4 %) and I (6·1 %) intakes, and canned fish contributed to vitamin D intake (13·4 %). Besides fish, contributions of mollusc and crustacean consumption to nutrient intakes should be considered from a public health viewpoint. Consuming seafood at least twice a week induces moderate inadequacies and risks of exceeding USL for some micronutrients, whereas macronutrient intakes remained imbalanced.

Social and cultural dimensions of hygiene in Cambodian health care facilities.

BACKGROUND: The frequency of bloodborne pathogen healthcare-associated infections is thought to be high in developing Southeast Asian countries. The underlying social-cultural logics contributing to the risks of transmission are rarely studied. This report provides some insights on the social and cultural factors that shape hygiene practices in Cambodian health care settings. METHODS: We conducted qualitative surveys in various public and private health facilities in Phnom Penh, the capital city and in provinces. We observed and interviewed 319 participants, health care workers and patients, regarding hygiene practices and social relationships amongst the health care staff and with patients. We also examined the local perceptions of hygiene, their impact on the relationships between the health care staff and patients, and perceptions of transmission risks. Data collection stem from face to face semi-structured and open-ended interviews and focus group discussions with various health care staffs (i.e. cleaners, nurses, midwives and medical doctors) and with patients who attended the study health facilities. RESULTS: Overall responses and observations indicated that hygiene practices were burdened by the lack of adequate materials and equipment. In addition, many other factors were identified to influence and distort hygiene practices which include (1) informal and formal social rapports in hospitals, (2) major infection control roles played by the cleaners in absence of professional acknowledgment. Moreover, hygiene practices are commonly seen as an unessential matter to be devoted to low-ranking staff. CONCLUSION: Our anthropological findings illustrate the importance of comprehensive understanding of hygiene practices; they need to be considered when designing interventions to improve infection control practices in a Cambodian medical setting.

Efficacy of an infant formula manufactured from a specific protein hydrolysate derived from whey protein isolate and concentrate produced by Société des Produits Nestlé S.A. in reducing the risk of developing atopic dermatitis.

The European Commission asked EFSA to evaluate the efficacy of an infant formula, containing a specific protein hydrolysate derived from whey protein isolate and concentrate and manufactured by Société des Produits Nestlé S.A., in reducing the risk of developing atopic dermatitis in infants with a family history of allergy. This was following the submission of a dossier by Société des Produits Nestlé S.A. to the European Commission, in the context of Regulation (EU) 2016/127. The protein hydrolysate from which the infant formula is produced is included in Annex I and II of Commission delegated Regulation (EU) 2016/127 as suitable protein source for the manufacture of infant and follow-on formulae. This opinion does not cover the assessment of the nutritional safety and suitability of the infant formula or the safety of the food enzymes used in the manufacture of the protein hydrolysate. The Panel considers that, in relation to the effect that is claimed, the infant formula under evaluation is not sufficiently characterised with respect to the molecular weight distribution of peptides. From the human intervention studies submitted, no conclusions could be drawn on the efficacy of the infant formula in reducing the risk of developing atopic dermatitis. The Panel concludes that a cause-and-effect relationship has not been established between the consumption of the infant formula under evaluation and the reduction in the risk of developing atopic dermatitis in infants with a family history of allergy.

Safety of calcidiol monohydrate produced by chemical synthesis as a novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on the safety of calcidiol monohydrate as a novel food (NF) pursuant to Regulation (EU) 2015/2283, including its bioavailability as a metabolite of vitamin D3 when added for nutritional purposes to food supplements. The NF is produced chemically. It is proposed in food supplements up to 10 µg/day for individuals ≥ 11 years of age, including pregnant and lactating women and up to 5 µg/day in 3- to 10-year-old children. The production process, composition, specifications and stability of the NF do not raise safety concerns. Animal and human data indicate efficient absorption. The NF contains a fraction of nanoparticles, which are fat soluble and unlikely to reach systemic distribution. There are no concerns regarding genotoxicity. Human adult studies do not raise safety concerns. Combined intake estimates of calcidiol from the NF and calcidiol and vitamin D from the diet were below the tolerable upper intake level (UL) for vitamin D for subjects above 11 years of age. The achieved mean serum 25(OH)D concentration in adults supplemented with 10 µg NF per day remained below 200 nmol/L. The Panel concludes that the NF is safe under the proposed conditions of use and use levels for individuals ≥ 11 years old, including pregnant and lactating women. The applicant did not provide data on the bioavailability and safety of the NF in children. The combined intake estimation in children (3-10 years) is close to the UL for vitamin D. Therefore, the Panel could not conclude on the safety of consumption of the NF in children (3-10 years) at the proposed daily intake. The NF is a bioavailable source of the biologically active metabolite of vitamin D, i.e. 1,25-dihydroxyvitamin D.

Novel foods in the European Union: Scientific requirements and challenges of the risk assessment process by the European Food Safety Authority.

The European Food Safety Authority (EFSA) has been involved in the risk assessment of novel foods since 2003. The implementation of the current novel food regulation in 2018 rendered EFSA the sole entity of the European Union responsible for such safety evaluations. The risk assessment is based on the data submitted by applicants in line with the scientific requirements described in the respective EFSA guidance document. The present work aims to elaborate on the rationale behind the scientific questions raised during the risk assessment of novel foods, with a focus on complex mixtures and whole foods. Novel foods received by EFSA in 2003-2019 were screened and clustered by nature and complexity. The requests for additional or supplementary information raised by EFSA during all risk assessments were analyzed for identifying reoccurring issues. In brief, it is shown that applications concern mainly novel foods derived from plants, microorganisms, fungi, algae, and animals. A plethora of requests relates to the production process, the compositional characterization of the novel food, and the evaluation of the product's toxicological profile. Recurring issues related to specific novel food categories were noted. The heterogeneous nature and the variable complexity of novel foods emphasize the challenge to tailor aspects of the evaluation approach to the characteristics of each individual product. Importantly, the scientific requirements for novel food applications set by EFSA are interrelated, and only a rigorous and cross-cutting approach adopted by the applicants when preparing the respective application dossiers can lead to scientifically sound dossiers. This is the first time that an in-depth analysis of the experience gained by EFSA in the risk assessment of novel foods and of the reasoning behind the most frequent scientific requests by EFSA to applicants is made.

Nutritional safety and suitability of a specific protein hydrolysate derived from whey protein concentrate and used in an infant and follow-on formula manufactured from hydrolysed protein by Danone Trading ELN B.V.

The European Commission asked EFSA to deliver an opinion on the nutritional safety and suitability of a specific protein hydrolysate. It is derived from whey protein concentrate and used in an infant and follow-on formula by Danone Trading ELN B.V, which submitted a dossier to the European Commission to request an amendment of Regulation (EU) 2016/127 with respect to the protein sources that may be used in the manufacture of infant and/or follow-on formula. This opinion does not cover the assessment of the safety of the food enzymes used in the manufacture of the protein hydrolysate. The protein hydrolysate under evaluation is sufficiently characterised with respect to the fraction of the hydrolysed protein. In the pertinent intervention study provided, an infant formula manufactured from the protein hydrolysate with a protein content of 2.3 g/100 kcal and consumed as the sole source of nutrition by infants for 3.5 months led to growth equivalent to a formula manufactured from intact cow's milk protein (2 g protein/100 kcal). No experimental data have been provided on the nutritional safety and suitability of this protein source in follow-on formula. However, given that it is consumed with complementary foods and the protein source is considered nutritionally safe and suitable in an infant formula that is the sole source of nutrition of infants, the Panel considers that the protein hydrolysate is also a nutritionally safe and suitable protein source for use in follow-on formula. The Panel concludes that the protein hydrolysate under evaluation is a nutritionally safe and suitable protein source for use in infant and follow-on formula, as long as the formula in which it is used contains a minimum of 2.3 g/100 kcal protein and complies with the compositional criteria of Commission Delegated Regulation (EU) 2016/127 and the amino acid pattern in its Annex IIIA.

Appropriate age range for introduction of complementary feeding into an infant's diet.

Following a request from the European Commission, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) revised its 2009 Opinion on the appropriate age for introduction of complementary feeding of infants. This age has been evaluated considering the effects on health outcomes, nutritional aspects and infant development, and depends on the individual's characteristics and development. As long as foods have an age-appropriate texture, are nutritionally appropriate and prepared following good hygiene practices, there is no convincing evidence that at any age investigated in the included studies (< 1 to < 6 months), the introduction of complementary foods (CFs) is associated with adverse health effects or benefits (except for infants at risk of iron depletion). For nutritional reasons, the majority of infants need CFs from around 6 months of age. Infants at risk of iron depletion (exclusively breastfed infants born to mothers with low iron status, or with early umbilical cord clamping (< 1 min after birth), or born preterm, or born small-for-gestational age or with high growth velocity) may benefit from earlier introduction of CFs that are a source of iron. The earliest developmental skills relevant for consuming pureed CFs can be observed between 3 and 4 months of age. Skills for consuming finger foods can be observed in some infants at 4 months, but more commonly at 5-7 months. The fact that an infant may be ready from a neurodevelopmental perspective to progress to a more diversified diet before 6 months of age does not imply that there is a need to introduce CFs. There is no reason to postpone the introduction of potentially allergenic foods (egg, cereals, fish and peanut) to a later age than that of other CFs as far as the risk of developing atopic diseases is concerned. Regarding the risk of coeliac disease, gluten can be introduced with other CFs.

Update of the tolerable upper intake level for vitamin D for infants.

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to revise the tolerable upper intake level (UL) for vitamin D for infants (≤ 1 year) set in 2012. From its literature review, the Panel concluded that the available evidence on daily vitamin D intake and the risk of adverse health outcomes (hypercalciuria, hypercalcaemia, nephrocalcinosis and abnormal growth patterns) cannot be used alone for deriving the UL for infants. The Panel conducted a meta-regression analysis of collected data, to derive a dose-response relationship between daily supplemental intake of vitamin D and mean achieved serum 25(OH)D concentrations. Considering that a serum 25(OH)D concentration of 200 nmol/L or below is unlikely to pose a risk of adverse health outcomes in infants, the Panel estimated the percentage of infants reaching a concentration above this value at different intakes of vitamin D. Based on the overall evidence, the Panel kept the UL of 25 µg/day for infants aged up to 6 months and set a UL of 35 µg/day for infants 6-12 months. The Panel was also asked to advise on the safety of the consumption of infant formulae with an increased maximum vitamin D content of 3 µg/100 kcal (Commission Delegated Regulation (EU) 2016/127 repealing Directive 2006/141/EC in 2020). For infants aged up to 4 months, the intake assessment showed that the use of infant formulae containing vitamin D at 3 µg/100 kcal may lead some infants to receive an intake above the UL of 25 µg/day from formulae alone without considering vitamin D supplemental intake. For infants aged 4-12 months, the 95th percentile of vitamin D intake (high consumers) estimated from formulae and foods fortified or not with vitamin D does not exceed the ULs, without considering vitamin D supplemental intake.

Dietary reference values for vitamin K.

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for vitamin K. In this Opinion, the Panel considers vitamin K to comprise both phylloquinone and menaquinones. The Panel considers that none of the biomarkers of vitamin K intake or status is suitable by itself to derive DRVs for vitamin K. Several health outcomes possibly associated with vitamin K intake were also considered but data could not be used to establish DRVs. The Panel considers that average requirements and population reference intakes for vitamin K cannot be derived for adults, infants and children, and therefore sets adequate intakes (AIs). The Panel considers that available evidence on occurrence, absorption, function and content in the body or organs of menaquinones is insufficient, and, therefore, sets AIs for phylloquinone only. Having assessed additional evidence available since 1993 in particular related to biomarkers, intake data and the factorial approach, which all are associated with considerable uncertainties, the Panel maintains the reference value proposed by the Scientific Committee for Food (SCF) in 1993. An AI of 1 µg phylloquinone/kg body weight per day is set for all age and sex population groups. Considering the respective reference body weights, AIs for phylloquinone are set at 70 µg/day for all adults including pregnant and lactating women, at 10 µg/day for infants aged 7-11 months, and between 12 µg/day for children aged 1-3 years and 65 µg/day for children aged 15-17 years.

Dietary Reference Values for riboflavin.

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derives dietary reference values (DRVs) for riboflavin. The Panel considers that the inflection point in the urinary riboflavin excretion curve in relation to riboflavin intake reflects body saturation and can be used as a biomarker of adequate riboflavin status. The Panel also considers that erythrocyte glutathione reductase activation coefficient is a useful biomarker, but has limitations. For adults, the Panel considers that average requirements (ARs) and population reference intakes (PRIs) can be determined from the weighted mean of riboflavin intake associated with the inflection point in the urinary riboflavin excretion curve reported in four intervention studies. PRIs are derived for adults and children assuming a coefficient of variation of 10%, in the absence of information on the variability in the requirement and to account for the potential effect of physical activity and the methylenetetrahydrofolate reductase 677TT genotype. For adults, the AR and PRI are set at 1.3 and 1.6 mg/day. For infants aged 7-11 months, an adequate intake of 0.4 mg/day is set by upward extrapolation from the riboflavin intake of exclusively breastfed infants aged 0-6 months. For children, ARs are derived by downward extrapolation from the adult AR, applying allometric scaling and growth factors and considering differences in reference body weight. For children of both sexes aged 1-17 years, ARs range between 0.5 and 1.4 mg/day, and PRIs between 0.6 and 1.6 mg/day. For pregnant or lactating women, additional requirements are considered, to account for fetal uptake and riboflavin accretion in the placenta during pregnancy or the losses through breast milk, and PRIs of 1.9 and 2.0 mg/day, respectively, are derived.

Genetic characterization of wild-type measles viruses in Cambodia.

Cambodian authorities in collaboration with the World Health Organization (WHO) are implementing a measles control plan in this measles endemic country. Genetic characterization of Cambodian wild-type measles viruses was performed to determine the genotypes involved in outbreaks, and to measure the level of virus circulation in a geographic area just beginning to implement the measles control program. Seventy-two sequences of the C terminus of the nucleoprotein gene of measles virus were obtained from 88 patients. Samples were taken from 35 among 519 outbreaks reported to the Cambodian National Immunization Program between March 2001 and June 2002. The sequences were grouped into 10 lineages which all belonged to genotype D5. The maximum nucleotide divergence was 1.3%.

Mechanistic information from analysis of molecular weight distributions of starch.

A methodology is developed for interpreting the molecular weight distributions of debranched amylopectin, based on techniques developed for quantitatively and qualitatively finding mechanistic information from the molecular weight distributions of synthetic polymers. If the only events occurring are random chain growth and stoppage (i.e., the rates are independent of degree of polymerization over the range in question), then the number of chains of degree of polymerization N, P(N), is linear in ln P(N) with a negative slope, where the slope gives the ratio of the stoppage and growth rates. This starting point suggests that mechanistic inferences can be made from a plot of lnP against N. Application to capillary electrophoresis data for the P(N) of debranched starch from across the major taxa, from bacteria (Escherichia coli), green algae (Chlamydomonas reinhardtii), mammals (Bos), and flowering plants (Oryza sativa, rice; Zea mays, maize; Triticum aestivum, wheat; Hordeum vulgare, barley; and Solanum tuberosum, potato), gives insights into the biosynthetic pathways, showing the differences and similarities of the alpha-1,4-glucans produced by the various species. Four characteristic regions for storage starch from the higher plants are revealed: (1) an initial increasing region corresponding to the formation of new branches, (2) a linear ln P region with negative slope, indicating random growth and stoppage, (3) a region corresponding to the formation of the crystalline lamellae and subsequent elongation of chains, and (4) a second linear ln P with negative slope region. Each region can be assigned to specific enzymatic processes in starch synthesis, including determining the ranges of degrees of polymerization which are subject to random and nonrandom processes.