Problems in Vegetable Canning

As the objective of canning to prevent the food from being spoiled before and during containment, as well  the canned product should in good quality distributed to the costumers. But there are sometimes found a litle products in the market not in good conditions and it usually caused by some problems when it was in the canning process. These very small amounts products generally produced and distributed by producers that not apply high standard in quality control.

There are quite a number of methods are used to prevent some problems when processing and preserving vegetables by canning.  And there are some recommendations you have read before in the previous article.  And the typical problems that could exist in vegetable canning are listed below.

Table 3. Problems in Vegetable Canning

Condition	Causes	Prevention
Food darkens in top of jar.	Liquid did not cover food. Food not processed long enough to destroy enzymes.  High vacuum not produced during processing.  Air was sealed in the jars either because headspace was too large or air bubbles were not removed	Cover food with liquid before capping Process each food by recommended method and for correct time. Pack and process as recommended. Use specified amount of headspace. Remove air bubbles with a non-metal spatula.
Black pots on underside of metal lid, may denote spoilage.	Natural compounds in some foods cause a black or brown deposit on the underside of the lid. This deposit does not mean the food is unsafe to eat. If jar has been sealed and then comes open, spoilage is evident. Do not use.	None. Use recommended processing methods and times; wipe jar rim before capping.
Cloudy liquid, may denote spoilage.	Spoilage (do not use). Minerals in hard water. Starch in vegetables. Fillers in table salt.	Process each food by recommended method and fo recommended time. Use soft water. None. Use a pure, refined canning salt.
Loss of liquid during processing. (Food may darken but will not spoil. Do not open jars to replace liquid.)	Food not heated before packing. Jars packed too tightly or too full. Air bubbles not removed before capping the jar Pressure canner not operating correctly. Pressure lowered suddenly. Starchy foods absorb liquid.	Heat food before packing Pack food more loosely. Leave recommended headspace. Remove air bubbles by running non-metal spatula between food and jar Pressure should not fluctuate during canning process. Keep heat constant during processing time Allow pressure to drop to zero naturally; wait 2 minutes before opening lid. None.
Jar seals, then comes open. Spoilage evident. (Do not use.)	Underprocessed. Particles of food left on the sealing surface. Hairline crack in jar.	Process each food by recommended method and for specified time. Wipe rim and threads of jar with clean, damp cloth before capping. Check jars prior to packing; discard ones unsuitable for canning.
Jars of food fail to seal.	Failure to follow instructions for using jar and lid. Food may have been forced up between the jar and lid during processing. Sealing compound defective. Edge of lid or rim of jar bent or chipped. Food particles on jar rim. Screw band tightened after jar removed from canner.	Carefully follow instructions. Use recommended headspace, do not let pressure fluctuate, allow pressure to drop to zero naturally. Use new lids. Check lids and jars prior to use. Wipe jar edge before putting on lid.  Allow jars to cool undisturbed.
Jars break.	Hairline crack in jar. Rack not used in bottom of canner. Screw bands applied too tightly so air could not escape during processing.	Check jars prior to processing. Be careful when packing and processing jars. Use rack and recommended amount of water. Apply screw bands more loosely.
Corn is brown.	Corn was too mature for canning. Liquid did not cover corn. Jars were processed at too high a temperature. Variety of corn used.	Use freshly picked corn. Cover corn with liquid before capping  jars. Keep pressure in canner at recommended pounds; gauge may be faulty and should be checked. Use different variety next year.
Green vegetables lose their bright color.	Heat breaks down chlorophyll, the green pigment in plants. Vegetables were too mature for canning.	None. Select young, tender vegetables.
Yellow crystals on canned green vegetables.	Glucoside, a harmless substance, naturally present in vegetables.	None.
White crystals in canned spinach.	Calcium and oxalic acid in spinach combine to form harmless calcium oxalate.	None.
White sediment in bottom of jars of vegetables. May denote spoilage.	Starch from the food. Minerals in hard water. Bacterial spoilage-liquid is usually murky, food soft. Do not use.	None. Use soft water. Process each food by recommended method and for specified time.

Partial Transesterification of Palm Oil with EtOH on Producing Diglycerides as Emulsifying Agent

ABSTRACT : The high of palm oil production growth push the need for diversification of palm oil into other products with high economic value. One of the products is an emulsifying agent. Emulsifying agent made from vegetable oils is biodegradable, so it does not pollute the environment, and sustainable supply is guaranteed because it comes from natural resources that can be renewed. In the production of an emulsifying agent made from raw palm oil, the transesterification reaction is an initial stage that will affect quality of the product.

This study aims to assess the condition of partial transesterification of palm oil. Transesterification process using palm oil and NaOH as a catalyst. Variables used are percent of the catalyst weight NaOH (0.1, 0.2, 0.3, and 0.4 {mol NaOH / kg oil}), the transesterification temperature (40, 50, 60, and 70 ° C), the transesterification time (15, 20, 25 and 30 minutes), and reactant ratios (1:3, 1:4, 1:5, and 1:6 mol {oil: ethanol mole}), to assess the impact on performance of diglycerides producted . Diglycerides product tested for its ability as an emulsifying agent in lowering the surface tension of water and in maintaining the stability of emulsion oil / water.

The results showed that the diglycerides producted has the ability lower the surface tension of water at the optimum percent of catalyst weight NaOH of 0.3 mol NaOH / kg of oil, transesterification temperature 50^oC, reaction time 30 minutes, and reactant ratio 1 oil mole : 6 ethanol mole.

Keywords : emulsifying agents, diglycerides, palm oil, NaOH, transesterification
Source >>

The Prospects of Coconut Processing Byproducts

ABSTRACT : The fruit flesh is the main component of coconut, while coconut fiber, shell, and water is a byproduct of fruit (by-product). With the production of coconuts in Indonesia, an average of 15.5 billion eggs per year, the total follow-up materials that can be gained 3.75 million tons of water, 0.75 million tons of charcoal, 1.8 million tons of coir fiber, and 3.3 million tons of coir dust as a byproduct.

Feasibility of processing byproduct of coconut fruit is very promising if planned and managed properly. Based on financial analysis in 2004, B / C and IRR coir processing into fibers and coir dust for 10 years was 3.58 and 76%; shell into charcoal for 5 years 1.11 and 23%, and coconut water become nata de coco for 5 years 1.32 and 32%.

Development of by-product processing industry should be supported by technical feasibility, especially the availability of raw material supply and marketing, and processing equipment that is suitable for processing fiber. To obtain sufficient raw materials for processing coconut husk required area 300 ha. Coir processing is integrated with the processing of coir dust into compost in order to obtain additional income. To produce 1 ton of fiber is obtained about 5 tons of coir dust. Location processing byproduct should be in the vicinity of the source of raw materials and to ensure continuity of supply and product marketing efforts suggested in the form of joint enterprise.

Keywords : Coconut, Cocos nucifera L., processing, byproduct
Source >>

Potential Evaluation of Freshwater Macroalgae Spirogyra sp., Hydrodictyon sp., Chara sp., Nitella sp., and Cladophora sp. as Source of Vegetable Oil

ABSTRACT : Research on the potential of Jatropha oil and Palm Oil as a renewable energy source has been widely reported. However, algae also has promising potential as a renewable energy source for raw materials of biodiesel production.

This study aims to obtain freshwater macroalgae species that contain a high oil content which can be converted into biodiesel. Green macroalgae samples collected from freshwater ponds and rivers in the Bogor Botanical Gardens, fields in Dago Biru (Bandung), Lido Lake in Sukabumi, and Lake Situ Bagendit in Garut.

Macroalgae samples were then cleaned and dried with sun-dried for 1-2 days and then re-weighed and then dried in an oven with a temperature of 60 ^oC for 2-3 days to obtain a constant dry weight. Samples of algae that have been dried and then extracted by maceration method using the solvent n-hexane for 2x24 hours, then partitioned with methanol and made soluble pigment removal using activated carbon for 2-3 days.

The extract then evaporated with a vacuum evaporator and obtain algae oil. The quality of the extracted algal oil then analyzed based on the value of acid number, saponification and iodine numbers using standard methods, ie successive FBI-03-A01, FBIA03-FBI-03 and A04-03. Results of quantification analysis of oil content of macroalgae were tested showed Nitella sp. 0.61% w / w, Cladophora sp. 0.57% w / w, Hydrodictyon sp. 0.54% w / w, Chara sp. 0.3% w / w, and Spirogyra sp. 0.15% b / b.

The test results show the quality of macroalgae oil acid number in the range of 55-143 mg KOH / g, which indicates high acid conditions in these algae oil, saponification value 400-500 mg KOH / g oil algae showed a short carbon chain that is in the range butyric acid (C-4) that is more suitable to utilize as a food source (such as supplements) and animal feed, and iodine number in the range of 3-28 g g I2/100 that within the standard requirements of the raw material of biodiesel.

Keywords : Macroalgae, biodiesel, algal oil
source >>

Guidance of Processing Times for Pressure Canning Vegetables

To prevent some problems when processing and preserving vegetables by canning there are some recommendations you should follow. Such as you should use recommended processing methods and times and wipe jar rim before capping. Below is a guidance list of processing times for pressure canning vegetables.

Table 2. Processing Times for Pressure Canning Vegetables

Vegetable	Pack	Jar Size	Minutes Processing Time	Dial gauge	Weighted gauge
				Canner gauge pressure at altitudes of
				0-2,000 ft	0-1,000 ft	Over 1,000 ft
				(pounds)	(pounds)	(pounds)
Asparagus	Raw or Hot	Pints	30	11	10	15
		Quarts	40
Beans, lima	Raw or Hot	Pints	40	11	10	15
		Quarts	50
Beans (snap, green, wax, or Italian)	Raw or Hot	Pints	20	11	10	15
		Quarts	25
Beets	Hot	Pints	30	11	10	15
		Quarts	35
Carrots	Raw or Hot	Pints	25	11	10	15
		Quarts	30
Corn, cream style	Hot	Pints	85	11	10	15
Corn, whole kernel	Hot	Pints	55	11	10	15
		Quarts	85
Greens (beet, Swiss chard, spinach)	Hot	Pints	70	11	10	15
		Quarts	90
Peas, fresh green	Raw or Hot	Pints	40	11	10	15
		Quarts	40
Peppers (hot or sweet)	Hot	Half-Pints	35	11	10	15
		Pints	35
Potatoes, white	Hot	Pints	35	11	10	15
		Quarts	40
Pumpkin	Hot	Pints	55	11	10	15
		Quarts	90
Sweet potatoes	Hot	Pints	65	11	10	15
		Quarts	90
Winter squash (acorn, banana, buttercup, butternut, hubbard)	Hot	Pints	55	11	10	15
		Quarts	90

That is the guidance list of processing times for pressure canning vegetables. I hope you can understand it easily and could practice it in your own agro industry. There is the last table related to pressure canning vegetables you should know, and I will proceed it in the next post. You can find it here.