W heat v a rieties and w h ea t b len d in g. 0 . H ubscii (Miihlenlab., 1938, 8, 97-—102).—Curves are given showing the effects of chemical treatm ent on various wheats and on blends thereof. E. A. F .
N ew d ough -ferm entation p ro ce ss. H . K u h l (Miihlenlab., 1938, 8, 89—94).—A m ixture of honey and leguminous flour is used as a leavening agent.
The development of micro-organisms is influenced by the nutrient, bacteria being favoured. E. A. F .
H ye-flour dough and w h eat-flour dough . In fluence of y e a st and of su g a r. A. Fo r n e t and
F . I h lo w (Miihlenlab., 1938, 8, 93—98).—Addition of yeast and/or sugar beyond 3% of yeast does not improve the qu ah ty of rye-flour dough. This is connected with th e properties of rye gluten, which also account for the steadily rising fornetograph compared with th e rise and fall in th e case of wheat. R ye gluten is of more im portance th a n has been thought.
E. A. F.
E ffect of d evelop m en t of b acteria on ch an ges in m ilk . T he con cept of “ suffocated " m ilk . J . Hani (Mitt. Lebensm. Hyg., 1937, 28, 315—356;
1938, 29, 57— 107).—The effect of lim itation of air supply on bacterial growth and production of odour in milk is investigated. 11 well-characterised odours which milk m ay acquire are tabulated, the characteris
tic odour of suffocated milk being “ sourish.” Change in odour is always associated with an increase in acidity. Milk kept in a th in layer does not sour so quickly as when air is limited, b u t its bacterial content is higher; acid-producing bacteria are inhibited in resence of air. Continuous aeration of m ilk is armful, b u t agitation lias little effect on the no.
of bacteria. In th e cream layers, th e more lim ited is th e supply of air tho fewer organisms grow, b u t in absence of air the acidity increases more rapidly and the sourish odour is produced. The surface layer, beinw richest in organisms, deteriorates most rapidly. I he organisms responsible for th e “ suffoc
a te d ” odour are, with few exceptions, Streptococcus laciis in conjunction with alkali-forming rods such as
Bact. fluorescens. E. C. S.
E ffect of co m m er cia l ste rilisa tio n on n utritive valu e of m ilk . V . E ffect on the vitam in -C of m ilk . K . M. Hen ry and S. K . Kon. V I. C om p arison of th e to ta l n u tritive value of ra w and co m m ercia lly ste rilise d m ilk s. K . M. Hen r y, E . W. Ik in, and S. K . .Kon. V II. C onclusions.
S. K . Kon (J. D airy Res., 1938, 9, 185—187, 188—
206, 207; cf. B., 1938, 579).—V. 15 samples each of raw and sterilised milk from th e same bulk analysed for vitam in-C by the chemical m ethod showed an average of 1-83 in th e former and 1-03 mg./lOO ml.
in the latter. Sterilisation caused a destruction of 43% of -O. A further reduction of 30% occurred on storing the la tte r for 4—6 weeks.
VI. The two types of m ilk were compared by 5 separate methods. Feeding equal am ounts of both to pairs of litter-m ate male ra ts showed no difference in growth rates, b u t sterilised milk was consumed more readily. R ats getting limited am ounts added to a basal ration grew better on raw th an on the heated milk, b u t addition of 5% of brewer’s yeast to the la tte r supplemented its deficiency for growth
purposes. R ats on raw milk to which 15% of cane sugar had been added grew b etter th an those on sim ilarly-treated sterilised milk. W ith sugar added a t th e ra te of 30 g. per 100 ml. of milk, ra ts on sterilised milk consumed less milk, grew poorly, and developed symptoms of beri-beri. The loss of -Bx in sterilised milk is th e limiting factor.
V II. Sterilisation of milk causes a 30% loss of -B v W. L. D.
S ta b ility of v itam in -D in irrad iated evaporated m ilk . C. H. Kr i e g e r and H. T. Sc o t t (Food Res.,
1938, 3 , 283—286).—No loss of vitam in-D occurs during one year’s storage a t atm . tem p., and little
loss in 2— 3 years. E. C. S .
M ethylene-blue redu ction te st [for m ilk ].
J . G. Da v i s (Dairy Ind., 1938, 3, 214—215).—The test depends on the concn. of dissolved 0 2 in milk, the reducing system in milk, an d tho reducing activity of th e micro-organisms. The advantages of the te s t are its quickness and reproducibility and th a t it measures th e activ ity of bacteria. The test is unsuitable for freshly pasteurised milk. M astitis streptococci in milk do n o t reduce the dye, b u t the accompanying leucocytes reduce it rapidly to a
pale blue colour. W. L. D .
P h o s p h a ta s e t e s t for p a s te u r is e d m ilk . H . L.
Sp e n c e r (Canad. D airy and Ice Cream J ., 1938, 17, No. 6, 21—22, 30).—The technique of th e K a y and Graham test under Canadian conditions is described.
W. L. D.
D etection and con trol of off-flavours in m ilk . T. S. Gilc h r ist (Canad. D airy and Ice Cream J ., 1938, 17, No. 6, 61—63, 82).—Sweetness in milk depends on lactose content, b u t th e pleasantness of taste depends on th e laotose-NaCl ratio. B utyric rancidity is due to lipase secreted by a few cows only and can be elim inated from m ilk and cream either by segregating th e m ilk of cows found affected by observation of individual samples or by pasteurisation a t 63° im mediately after milking. An oxidised flavour is m ostly due to contam ination with Cu and Fe during processing. Medicinal flavours are due to residues of Cl2 sterilisers left on equipm ent
acting on milk. W. L. D.
C ontrolling th e flavour of cream ery b u tter.
B. W . Ha m m e r (Canad. D airy and Ice Cream J ., 1938, 17, No. 6, 23—25).— Off-flavours in cream are communicated to butter. Cream flavours are reduced by pasteurisation, aeration, or vac. treatm ent. The m ain flavour of b u tter enters from starters and is due to th e composite effect of volatile acids and Ac20 . A m ethod of increasing the Ac20 content of starters is to add citrate to the culture. Keeping quahty is associated w ith flavours since th e development o f the latter to various degrees influences th e fo rm e r.
Control of deterioration of b u tter depends on proper cream pasteurisation and prevention of after-con-
tam ination. W- L. D.
D istrib u tio n of m o istu re and s a lt in cream ery b u tter. E. G. Ho o d and A. II. W h i t e (Canad.
D airy and Ice Cream J ., 1938, 17, No. 5, 49—55, S2; No. 6,49-—55, 82).—Samples taken from different parts of a churning w ithin th e b u tter churn when
Cl. X IX .—FOODS. 1 0 9 3
ready for boxing showed wide variations in H 20 and NaCI content. Variations were also shown by composite sampling of different churnings from th e same churns. This lack of uniform ity was due to type, level, and mechanical condition of the churn, lack of uniform methods of m anufacture, and a tte n tion to detail. Greater uniform ity in NaCI content was obtained by dividing the NaCI into two equal portions and spreading each portion separately over half the b u tter in the churn. Variation in a churning should be >0-25% in NaCI and H 20 contents and, until this level of uniform ity is reached, too much dependence should not be placed on the results of the analysis o f a composite sample. W. L. D.
C om parative m eth od s and m ed ia u sed in m icrob iological exam in ation of cream ery b utter.
I. Y east and m ou ld cou n ts. G. W. S i t a d w i o k ,
jun. (Food Res., 1938, 3, 287—298).—Fresh and dried potato-glucoso agar (I) and dried m alt-, peptonised milk-, whey-, and wort-agars adjusted to p n 3-5 were examined. B utters w ith few organisms gave higher counts a t a dilution of 1 : 2, th e unsalted being unaffected by th e medium, the salted m ost consistent on (I). W ith approx. 200 moulds and yeasts per c.c. the 1 :1 0 dilution gave th e most consistent results, (I) being preferable for salted butters and
wort-agar for unsalted. E. C. S.
H e a t-re n d e re d b u t t e r . W . Ri t t e r (Mitt.
Lebensen. Hyg., 1937, 28, 206—214).—The keeping quality of b u tter is increased by boiling and separation of the serum and pouring off th e fat for storage.
The fat sterilisation tem p, reaches 105— 110°. Such fa t is comparatively free from lecithin. The H 20 content should be >0-1% , a level which can bo reached b y heating the separated fa t a t 100° in heavily-tinned vessels. To p re v e n t. the formation of large crystals of fat and to m aintain smoothness in the solid product, holding a t 30—33° during crystallisation is recommended. Tallowiness some
times develops and the keeping quality can be followed by increases in peroxide-0 and response to the
R reis test. W. L. D.
S pread in g capacity of b utter. I. G. W. S. Bl a i r
(J. D airy Res., 1938, 9, 208—214).—Cylinders of b utter of 4 cm. diam eter and 2 cm. height are subject to compression by wts. (IF), the tim e (f) taken to give a compression o f 0-79 cm. a strain of 0-5), being measured, tj is th en given by the expression 0-01896174 megapoises. A simple rheometer is described which, in spito of tem p, control not being exact, gives an effective measure of butter-hardness.
Results are given which also show the extent to which the phenomenon of “ false body ” occurs in reworked
b utter. W. L. D.
E nzym ic behaviour (aldehyde reductase and p eroxid ase reaction s) in cream and w h ey b utters.
W . Ri t t e r (Mitt. Lobensm. Hyg., 1937, 2 8 , 197—
205).—T he Ca contents of th e butterm ilk sera separated from cream and whey b u tter are 0-150 and 0-077% respectively. Sera from b u tter made from unpasteuriscd cream cause rapid bleaching in th e Schardinger reaction, b u t th a t from whey b u tter does not bleach the reagent. The peroxidase re
action is given by sera of b u tter from unpasteurised cream b u t only faintly by heated blended b u tter sera. This reaction is not given by sera of b u tter from pasteurised cream b u t m ay be positive in some samples of such b u tter on prolonged storage. Con
tam ination w ith Cu will give a positive reaction.
The pasteurisation of cream prevents reactions of enzymes being used to characterise butters.
W . L. D.
M odern m eth o d s of exa m in in g m a rga rin e.
L. Er l a n d s e n (Allgem. Oel- u. F ett-Z tg., 1938, 3 5 , 237—240).—Recently developed physical and chemical methods for th e evaluation and analysis of margarine
are briefly reviewed. E . L.
Ice-cream m a k in g . A. Po m t a (Dairy Ind., 1938, 3 , 235— 236, 240).—15 special preps, in which soft and hard, minced and dried fruits are incorporated
are described. W. L. D.
F rozen fru its for u se in ice cream . H. A,
Sj i a l l i t e l d (Canad. D airy and Ice Cream J ., 1938, 17, No. 6, 32—34).—Addition of frozen strawberries, raspberries, cherries, peaches, and apricots in whole, crushed, or quartered form in the proportion of 8, 10, and 12% to ice cream gave appealing flavours which were best for the highest proportion of fruit and when th e fru it had been preserved in frozen condition with 2-5 times th e am ount of sugar.
W . L. D.
S ta le fla v o u rs i n ice c r e a m . K. G. We c k e l
(Canad. D airy and Ice Cream <T., 1938, 17, No. 6, 57—59).—Such flavours are defined by lack of freshness and are m ainly due to fat which m ay have a stale flavour or have absorbed foreign flavours.
Cream and dried milk should be free from contam in
ation w ith Cu and Fe, and a stale storage flavour sometimes occurs in winter cream. Powdered egg products undergo flavour changes in storage, and nuts which have become rancid im part th eir flavour to ice cream. Sorupulous cleanliness of equipm ent and the use of anti oxidants, such as oat flour, preserve
the fresh flavour. W. L. D.
C h em ical p ro cesses in ch eese rip en in g. G.
Sc h w a r z (Angew. Chem., 1938, 5 1 , 521-—524).—A review.
; Im p rovin g quality of m ilk for ch eesem ak in g.
W . H . Sb r o u l e (Canad. D airy and Ice Cream J ., 1938, 17, No. 6, 65).—Good-quality raw milk is necessary and first-grade milk tested by th e methylene- blue or resaurin tests only should be used in order to give uniformly high-grade cheese. W . L. D.
C alcium and phosphorus con tents o f ty p es of B r itish ch eese at variou s sta g e s d urin g m a n u facture and rip en ing. E. G. V. Ma t t i c k (J. D airy Res., 1938, 9 , 233—241).—The loss of Ca an d P a t various stages in th e m anufacture of Cheddar, Cheshire, Leicester, Lancashire, and Stilton cheese m ade from the same bulk of milk has been investig
ated. After pressing for 24 hr., the ash, Ca, and P retained in hard cheese were alm ost identical, being 53, 66, and 55% of those constituents in th e raw milk, respectively. Stilton a t 3 days contained only 26,
18, and 42% of these constituents, respectively, and heavy losses occurred during ripening. W . L. D.
1 0 9 4 BRITISH CHEMICAL AND PHYSIOLOGICAL ABSTRACTS.—B.
V olatile acid s of ch eese. I. R eten tive p ow er of ch eese and its co n stitu en ts. E. R . H iscox and
J . Ha r r i s o n. II. M ethods of extraction . E. R.
H iscox, J . Ha r r i s o n, and J . Z. W o l f (J. D airy Res., 1938, 9, 215—226, 227—232).—I. D irect steam- distillation of cheese gives low vals. owing to the retarding effect of fa t on the distillation of the higher volatile fa tty acids and the perm anent retention of some in the protein. More accurate comparative vals. are obtained by collecting steam distillates of twice th e vol. of th e cheese suspensions th an with exhaustive distillation up to 5 vols.
II. Cheese is extracted first w ith H 20 and then w ith E t20 to extract the fat. The free fa tty acids of the fa t are separated with aq. NaOH. These fractions are then steam-distilled. Vals. are given which are 4—5 times those given by direct distillation of the
cheese. W. L. D.
D etection of gela tin in ch eese. T. v o n Fe l l e n- b e r g (Mitt. Lebensm. Hyg., 1938, 2 9 , 10— 15).—
Degradation products (I) of casern give pptn. re
actions somewhat similar to those given by gelatin (II). They m ay be removed by treatm ent w ith a m oderately high concn. of CuS04, and after removal of Cu with H 2S, (II) is detected by pptn. w ith tannin.
Only so much CuS04 as is necessary to complete th e pptn. of protein should be added, since (II) is liable to be pptd. by excess. The procedure outlined does not give quant, results, b u t even 0-1% of (I) will give an opalescence. (I) give a positive result with the Jaff6-Folin reaction for creatinine. E. C. S.
A n a ly sis of ca sein . J . De l o r m e (Rev. Gen.
Mat. Plast., 1938, 1 4 , 109— 110).—Methods of deter
mining hum idity, acidity, and ash content are reviewed. Vitreosil apparatus is recommended for
ash determ inations. F . McK.
D eterm in ation of fat in e g g p reserv es. R.
Vi o l l i e r (Mitt. Lebensm. H yg., 1937, 2 8 , 215—
220; cf. B., 1937, 1124).—The m ethod used in th e previous work was th a t of B aur and Barschall (Z.
Unters. Nahr. Genussm., 1909,1 7 , 417), which gives higher vals. th a n extraction with E t20 or light petroleum. The am ounts of extract obtained w ith various solvents, w ith and w ithout treatm ent with H 2S 0 4, are recorded. The differences are attrib u ted to variations in the am ount of lecithin extracted.
The need for uniform ity of procedure is stressed.
E. C. S.
D eterm ination of eg g con tent of Italian p a stes.
D eterm in ation of ch olesterol. I, II. J. Te r r i e r
(Mitt. Lebensm. Hyg., 1937, 2 8 , 184—197; 1938, 2 9 , 15— 22).—I. Of the methods available, viz., determ ination of H 20 and E t20 extract, of lecithin- P 20 5, of sol. protein, and of cholesterol (I), the last is th e m ost trustw orthy since (I) is least affected by drying and ageing of th e paste. Owing, however, to the possibility of (I) having been added, reliance should not be placed on this determ ination alone. A procedure, based on pptn. with digitonin, is described.
The egg content is then calc, from the expression 50{% (I) — 0-018}/0-023, since it has been found th a t eggs contain, on the average, 230 mg. of (I) per 50 g. [This calculation appears to contain a tenfold-error.]
II . The m ethod of determ ination is improved by decomp, th e (I) digitonide by boiling w ith xylene and weighing the (I) liberated. The procedure is
described. E. C. S.
Curing of m ea t. 0 . J o n e s (Food Manuf., 193S, 1 3 , 236—237).—The ra te of penetration of NaCI into muscle varies inversely as th e electrical resistance, which increases according to the am ount of exercise the anim al has had ju st prior to death. Meat from exercised pigs tain ts more readily th an th a t of farm- killed animals. The red colour of cured m eat is due to nitrosohajmoglobin, and its change to brown is due to th e form ation of methremoglobin by reduction or sometimes by th e action of B. ce.re.us. W . L . D.
P ro g r ess in m e a t canning. T. C r o s b i e - W a l s h
(Food Manuf., 1938,1 3 , 231—233).—A review dealing with closure of tins, can cooling, and m aturing of
m eat. W . L . D.
P reserva tio n of h a lib u t liv ers and in testin es.
H. N. B r o c k l e s b y and K . G r e e n (Progr. Rep.
Fish. Res. Bd. Canad., 1938, No. 36, 7— 10).—The effects of borax, salicylic acid, H 3B 0 3, NaCl, AcOH, C H ,0 , NaHSOg, N aN 0 2, BzOH, N a N 0 3, and NaOBz as preservatives of m acerated livers have been investigated, using to tal volatile N as a measure of bacterial spoilage. Only the first six were effective.
CH20 is recommended as allowing greater subsequent ease of digestion by alkali and pepsin and preventing th e loss of vitamin-^, which occurs in putrefying
livers or intestines. T. F . D.
S olu b le so lid s in citru s fru its. E . T. B a r t h o l o m e w , W . B. S i n c l a i r , and B. E. J a n e s (Science, 1938, 8 7 , 584).—D ata for Valencia fruits are reported
and discussed. L . S . T.
B y-p rod ucts from citru s fru its. J . L . S a r i n ( J . Indian Chem. Soc., Ind ust. Ed., 1938, 1, 59—
62).-—A description is given of m ethods suitable for the extraction of Ca citrate, essential oils, and pectin from Indian citrus fruits. W . A. R.
S pray-resid u e rem o va l from ch erries. H . C.
M c L e a n and A. L . W e b e r ( J . Econ. Entom ., 1937, 3 0 , 777—779).-—Following spraying w ith P b arsenate, cherries already packed in crates were satisfactorily washed by dipping in 1% HC1 and gentle agitation for 30—60 sec. and subsequently washing twice w ith H 20 . F ru it sprayed w ith CaO -bentonite-S was similarly treated with 0-25% HC1. A wetting agent facilitated spray removal in both cases.
A. G. P.
M icro-m eth od for identification and d ete rm in ation of ethylen e in rip en in g fr u its . J . B. N i e d e r l
and M. W . B r e n n e r (Mikrochem., 1938, 2 4 , 134— 145).—The C2H 4 is converted into C2H 4B r2 (I) by absorption in liquid B r in an apparatus designed to remove small am ounts of C2H 4 from large vols. of air. The (I) is converted into C2H 2 by heating with E tO H -K O H solution and th e C2H 2 absorbed as Ag2C2 in E t0 H -A g N 0 3 solution in a modification of the Pregl OMe apparatus. Using the above reactions, it has been proved th a t approx. 0-1—0-2 ml. of C2H4 per 100 lb. of fruit is evolved by bananas during
ripening. L . S . T.
Cl. X IX .—FOODS. 1095
S torin g d esser t grap es in Provence [France].
G. Ma t h i e u (Compt. rend. Acad. Agric. France, 1938, 24, 307—311).—Late varieties of grapes w ith a sugar : acid ratio of 30 should be chosen for storage, and kept in chambers a t 2° w ith an atm . a t 80%
R .H . A. W. M .
H ydrogen sw e lls in canned fru its. W. B. Ad a m
(Chem. and Ind., 1938, 57, 682—687; cf. B., 1938, 843).—The rapidity of perforation after doming and the period of keeping a t 35° required to reach 25%
of loss by H 2 swells were determined, 10 varieties of fru it being examined and different types of tinplate and methods of sealing and lacquering being used.
To guard against excessive losses it is recommended th a t rimming steels low in S, w ith a Cu : S ratio
> 2 , and free from inclusions of massive cementite, should be used and improved m ethods of tinning, so as to reduce porosity, should be applied. In can- making, the area of exposed steel should be a t a min., the expansion rings of the ends should give a high doming pressure, and lacquering should be developed to give complete protection to exposed steel. Beet sugar should be used where possible;
unblued sugar is essential. W ith sweet cherries, and sometimes with ripe greengages and bilberries,
\ \ oz. of citric acid per gall, should be added.
For gooseberries, yellow plums, and greengages plain cans should be used. Recommendations are also made for details of the canning process, minimis
ing disturbance during transport, and storing under as cool conditions as possible. E. C. S.
D etection of g lu cose syrup in ja m s and honeys.
G. D. El s d o n (Analyst, 1938, 63, 422—423).—The f.p. of 10% wt./vol. solutions of honey lie between 0-883 and 0-919, so th a t any appreciable addition of glucose (I) syrup should bo detectable by determ ining this val. The variation of f.p. in th e case of jam s is too great for this to be possible. The detection and determ ination of (I) by simple ferm entation with
yeast is described. E . C. S.
Iodine content of O hio veg eta b les. C. Di e t z
(Food Res., 1938, 3, 359—365).—The I contents of lettuce, tomatoes, and asparagus are recorded. The I content of the last two was increased by application
of K I to the soil. E. C. S.
V itam in-C content of vegeta b les. IX . In
fluence of m eth od of cooking on vitam in -C con
ten t of cabbage. M.v W e l l i n g t o n and D. K.
Tr e s s l e r (Food Res., 1938, 3, 311—316; cf. B., 1937, 183).—W hen boiled, < 1 7 % of th e vitamin-C was destroyed, b u t about 67% was extracted by the cooking-H20 when finely-shredded cabbage was used.
Tr e s s l e r (Food Res., 1938, 3, 311—316; cf. B., 1937, 183).—W hen boiled, < 1 7 % of th e vitamin-C was destroyed, b u t about 67% was extracted by the cooking-H20 when finely-shredded cabbage was used.